Pacific Maritime Association v. National Labor Relations Board

FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

INTERNATIONAL LONGSHORE No. 23-632

AND WAREHOUSE UNION;

NLRB No.

INTERNATIONAL LONGSHORE

19-CD-269637

AND WAREHOUSE UNION,

LOCAL 19,

Petitioners, OPINION

v.

NATIONAL LABOR RELATIONS

BOARD,

Respondent,

INTERNATIONAL ASSOCIATION

OF MACHINISTS AND

AEROSPACE WORKERS,

DISTRICT 160, LOCAL LODGE

289,

Intervenor.

PACIFIC MARITIME No. 23-658

ASSOCIATION,

NLRB No.

Petitioner,

19-CD-269637

v.

NATIONAL LABOR RELATIONS

2 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

BOARD,

Respondent,

INTERNATIONAL ASSOCIATION

OF MACHINISTS AND

AEROSPACE WORKERS,

DISTRICT 160, LOCAL LODGE

289,

Intervenor.

NATIONAL LABOR RELATIONS No. 23-780

BOARD,

NLRB No.

Petitioner,

19-CD-269637

v.

INTERNATIONAL LONGSHORE

AND WAREHOUSE UNION;

INTERNATIONAL LONGSHORE

AND WAREHOUSE UNION,

LOCAL 19,

Respondents,

INTERNATIONAL ASSOCIATION

OF MACHINISTS AND

AEROSPACE WORKERS,

DISTRICT 160, LOCAL LODGE

289,

Intervenor.

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 3

INTERNATIONAL ASSOCIATION No. 23-793

OF MACHINISTS AND

NLRB No.

AEROSPACE WORKERS,

19-CD-269637

DISTRICT 160, LOCAL LODGE

289,

Petitioner,

v.

NATIONAL LABOR RELATIONS

BOARD,

Respondent,

On Petition for Review of an Order of the

National Labor Relations Board

Argued and Submitted November 15, 2024

San Francisco, California

Filed June 18, 2025

Before: Sidney R. Thomas and Eric D. Miller, Circuit

Judges, and Lee H. Rosenthal, District Judge. *

Opinion by Judge Miller;

Concurrence by Judge Miller

*

The Honorable Lee H. Rosenthal, United States District Judge for the

Southern District of Texas, sitting by designation.

4 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

SUMMARY *

National Labor Relations Act

The panel (1) granted petitions for review by the

International Longshore and Warehouse Union (ILWU) and

the Pacific Maritime Association (PMA), (2) denied a

petition for review by the International Association of

Machinists and Aerospace Workers (IAM), (3) denied a

cross-petition for enforcement by the National Labor

Relations Board, and (4) vacated the Board’s order directing

ILWU to cease and desist from pursuing maintenance work

for SSA Terminals at Terminal 5 in the Port of Seattle.

This case arose from a jurisdictional dispute between

ILWU and IAM, both of which claimed the right under

collective bargaining agreements to perform maintenance

work for SSA. Pursuant to section 10(k) of the National

Labor Relations Act, SSA asked the Board to decide which

union should perform the work. The Board assigned the

work to IAM, prompting ILWU to pursue a grievance

against SSA under its collective bargaining agreement,

seeking the value of the work assigned to IAM.

After an arbitrator found in ILWU's favor, SSA filed an

unfair labor practice charge against ILWU, alleging that

ILWU violated section 8(b)(4)(D) of the Act because its

pursuit of the grievance was intended to coerce SSA into

assigning the work to ILWU. ILWU defended itself by

invoking the work-preservation defense, which protects

“primary” union activity—activity intended to accomplish

*

This summary constitutes no part of the opinion of the court. It has

been prepared by court staff for the convenience of the reader.

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 5

some goal within the confines of the employer-employee

relationship—as opposed to impermissible “secondary”

union activity—activity that has the goal of inducing an

employer to take action against a third party with which the

union has a dispute. See NLRB v. International

Longshoremen’s Ass’n (ILA), 447 U.S. 490 (1980).

The Board determined that the work-preservation

defense is not available in pure jurisdictional disputes, like

this one, where multiple unions have valid contractual

entitlements to the disputed work directly with the

employer. The Board ordered ILWU to cease and desist

from pursuing the maintenance work at Terminal 5.

The panel held that the Board’s position was foreclosed

by International Longshore and Warehouse Union v. NLRB

(Kinder Morgan), 978 F.3d 625, 637 (9th Cir. 2020), which

held that “[a] valid work-preservation objective provides a

complete defense against alleged violations of section

8(b)(4)(D), as well as against jurisdictional disputes under

section 10(k).” Pursuant to Kinder Morgan, a union charged

with an unfair labor practice under section 8(b)(4)(D) may

raise a work-preservation defense even when the union is not

alleged to have engaged in illegal secondary activity. The

Board erred by refusing to entertain ILWU’s work-

preservation defense under Kinder Morgan. Accordingly,

the panel vacated the Board’s order and remanded for the

Board to evaluate the merits of the defense in the first

instance.

Concurring, Judge Miller wrote separately to express his

view that Kinder Morgan was wrongly decided and should

be reconsidered en banc. Because the ILA work-

preservation defense allows a union to demonstrate that it

did not act with an illegal secondary objective, the Board has

6 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

historically entertained the defense only when a union is

alleged to have engaged in secondary activity in violation of

section 8(b)(4)(B). Kinder Morgan applied an affirmative

defense that the Supreme Court created to cabin the reach of

one statutory provision, section 8(b)(4)(B), to cases arising

under a separate statutory provision, section

8(b)(4)(D). Grafting the ILA work-preservation defense

onto section 8(b)(4)(D), as Kinder Morgan did, undermines

the jurisdictional dispute-resolution scheme enacted by

Congress. It is not supported by precedent, creates a circuit

conflict, and undermines Congress’s decision to empower

the Board to resolve jurisdictional disputes.

COUNSEL

Robert S. Remar (argued), Law Office of Robert Remar, San

Francisco, California; Robert H. Lavitt, Travis Lavenski,

and Julian Gonzalez, Barnard Iglitzin & Lavitt LLP, Seattle,

Washington; Lindsay R. Nicholas, Leonard Carder LLP,

Oakland, California; Michael E. Kenneally (argued) and

Jonathan C. Fritts, Morgan Lewis & Bockius LLP,

Washington, D.C.; Geoffrey J. Rosenthal, Morgan Lewis &

Bockius LLP, Philadelphia, Pennsylvania; Gregory Nelson,

Morgan Lewis & Bockius LLP, New York, New York; for

Petitioners.

Micah P.S. Jost (argued), Attorney; Kira D. Vol, Supervising

Attorney; David Habrndtreit, Assistant General Counsel;

Ruth E. Burdick, Deputy Associate General Counsel; Peter

S. Ohr, Associate General Counsel; Jennifer A. Abruzzo,

General Counsel; National Labor Relations Board,

Washington, D.C.; for Respondent.

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 7

David A. Rosenfeld (argued), Weinberg Roger & Rosenfeld,

Emeryville, California, for Intervenor.

OPINION

MILLER, Circuit Judge:

Sometimes multiple unions have irreconcilable

contractual rights to perform the same work for the same

employer. The resulting disputes—which the employer

cannot resolve without breaching its obligations to one of the

unions—are known as “jurisdictional disputes.” See USCP-

WESCO, Inc. v. NLRB, 827 F.2d 581, 583 (9th Cir. 1987).

This case arises out of a jurisdictional dispute between

the International Longshore and Warehouse Union (ILWU)

and the International Association of Machinists and

Aerospace Workers (IAM). Both claim the right under

collective bargaining agreements to perform certain work for

SSA Terminals. Unable to resolve the dispute itself, SSA

asked the National Labor Relations Board to decide which

union should perform the work. The Board assigned the

work to IAM, prompting ILWU to pursue a grievance under

its collective bargaining agreement. The Board then filed an

unfair labor practice charge against ILWU, alleging that its

pursuit of the grievance was illegal. ILWU defended itself

by invoking the work-preservation defense. That defense

protects “primary” union activity—that is, activity intended

to accomplish some goal within the confines of the

employer-employee relationship. See NLRB v. International

Longshoremen’s Ass’n (ILA), 447 U.S. 490, 504 (1980). But

the Board determined that the defense does not apply in

disputes, like this one, where multiple unions have valid

8 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

contractual entitlements to the disputed work directly with

the employer.

Whatever the merits of the Board’s position as a matter

of first principles, it is foreclosed by our decision in

International Longshore and Warehouse Union v. NLRB

(Kinder Morgan), 978 F.3d 625 (9th Cir. 2020). We

therefore grant the petitions challenging the Board’s order

and deny the Board’s cross-petition for enforcement.

I

ILWU represents longshore workers at ports along the

Pacific Coast, including the Port of Seattle. It has a

longstanding collective-bargaining relationship with the

Pacific Maritime Association (PMA), an association of

businesses that employ longshore workers. See Kinder

Morgan, 978 F.3d at 630. ILWU and PMA have negotiated

a master collective bargaining agreement, the Pacific Coast

Longshore Contract Document (PCLCD), which is binding

on all PMA-member employers.

For many decades, ILWU and PMA have quarreled over

the extent to which PMA-member employers may use

technology to replace the work traditionally performed by

union longshore workers. In 2008, ILWU and PMA

addressed that issue when they negotiated the current version

of the PCLCD. Section 1.72 allows PMA-member

employers to introduce automation at their marine terminals.

In exchange, it expands ILWU’s jurisdiction to cover the

“installation, reinstallation, removal, maintenance and

repair, and associated cleaning of such new technologies”—

which we will refer to simply as “maintenance work”—at

certain qualifying ports.

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 9

In 2018, SSA Terminals, a PMA-member employer,

began operating Terminal 5 of the Port of Seattle as a marine

terminal, making Terminal 5 subject to section 1.72. But that

presented a conflict. Although section 1.72 required SSA to

assign the maintenance work to mechanics represented by

ILWU, SSA had a separate bilateral collective bargaining

agreement with IAM, guaranteeing IAM-represented

mechanics the right to “perform all [maintenance] work

. . . at all Puget Sound Region Intermodal, Marine or

Container Terminals,” including Terminal 5. SSA initially

assigned the maintenance work to mechanics represented by

ILWU. In response, IAM threatened “economic action” at

Terminal 5. Caught in the middle of the jurisdictional dispute

between the two unions, SSA turned to the Board for help.

The National Labor Relations Act, ch. 372, 49 Stat. 449

(1935) (29 U.S.C. § 151 et seq.), as amended by the Taft-

Hartley Act, ch. 120, 61 Stat. 136 (1947), establishes a two-

step mechanism to allow the Board to resolve jurisdictional

disputes. First, section 8(b)(4)(D) makes it an unfair labor

practice to “threaten, coerce, or restrain” an employer with

the object of forcing that employer to “assign particular work

to employees in a particular labor organization . . . rather

than to employees in another labor organization.” 29 U.S.C.

§ 158(b)(4)(D). Second, when the Board finds cause to

believe that section 8(b)(4)(D) has been violated, section

10(k) empowers it to hold a hearing and to award the

disputed work to one of the competing unions. 29 U.S.C.

§160(k). The Board considers a variety of factors at a 10(k)

hearing, including the skills of the competing unions, the

unions’ history of performing the relevant work, the

employer’s preference, the different collective bargaining

agreements, and the economic efficiency of the employer’s

10 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

business. See International Ass’n of Machinists, Lodge

1743, 135 N.L.R.B. 1402, 1410–11 (1962).

SSA invoked that mechanism here. First, it filed an

unfair labor practice charge against IAM, alleging that its

threat of “economic action” violated section 8(b)(4)(D). That

triggered section 10(k), so the Board held a hearing to

determine if the disputed work should be awarded to

mechanics represented by ILWU or to those represented by

IAM. After considering the relevant factors, the Board

assigned the work to IAM-represented mechanics.

ILWU refused to accept the Board’s decision, instead

pursuing a grievance under the PCLCD seeking the value of

the work assigned to IAM. ILWU alleged that SSA had

violated section 1.76—which requires SSA to “defend” the

assignment of work to ILWU-represented mechanics “in any

legal proceeding”—by failing to state a preference for

ILWU-represented mechanics at the section 10(k) hearing.

An arbitrator found that SSA had violated section 1.76 and

ordered it to pay ILWU for “lost work opportunity claims for

any future [Terminal 5 maintenance] work not performed by

ILWU-represented [m]echanics.”

From SSA’s perspective, the arbitration award made the

Board’s section 10(k) determination a nullity: SSA could

either reassign the work back to ILWU or else be forced to

pay twice. So SSA filed another unfair labor practice charge

with the Board. This time, SSA, joined by PMA, alleged that

ILWU had violated section 8(b)(4)(D) because pursuing the

grievance was intended to coerce SSA into assigning the

work to mechanics represented by ILWU rather than IAM.

See 29 U.S.C. § 158(b)(4)(D).

The unfair labor practice charge proceeded to a hearing

before an ALJ. ILWU did not dispute that pursuing a

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 11

grievance in defiance of a section 10(k) award can violate

section 8(b)(4)(D). Rather, it argued that its conduct was

immunized by the work-preservation affirmative defense.

Specifically, ILWU argued that pursuing the grievance was

“primary” activity because it sought to accomplish a goal

within the confines of its relationship with SSA—namely, to

get SSA to honor its contractual obligations to assign the

maintenance work to ILWU workers. The ALJ rejected

ILWU’s defense, and the Board affirmed. The Board held

that the work-preservation defense is unavailable in pure

jurisdictional disputes. Permitting a union to raise that

defense, it observed, would subvert Congress’s intention to

“afford employers protection when their actions conform to

a Board determination under section 10(k).” The Board

ordered ILWU to cease and desist from pursuing the

maintenance work at Terminal 5 and to notify its mechanics

of their obligation to do the same.

Four petitions followed, all of which have been

consolidated here. ILWU and PMA each petition for review

of the Board’s order finding that ILWU violated section

8(b)(4)(D). They argue that the Board erred in rejecting

ILWU’s work-preservation defense. In the alternative, they

contend that the Board’s section 10(k) work award was not

supported by substantial evidence. IAM also petitions for

review. Although it agrees with the Board’s legal and factual

conclusions, it argues that the Board’s remedy is inadequate

to prevent ILWU from illegally pursuing disputed work at

Terminal 5 and other terminals along the Pacific Coast.

Finally, the Board cross-petitions for enforcement of its

order. See 29 U.S.C. § 160(e), (f).

12 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

II

The parties agree on several preliminary points. They

agree that this is a genuine jurisdictional dispute: ILWU and

IAM both had valid contracts with SSA (or in ILWU’s case,

with PMA, to which SSA was bound), and SSA could not

simultaneously comply with its obligations under both

contracts. They also agree that when both ILWU and IAM

pursued the maintenance work, it was appropriate for the

Board to resolve the dispute under section 10(k). They even

agree that ILWU’s pursuit of a grievance in arbitration

constituted a prima facie violation of section 8(b)(4)(D).

They disagree, however, on whether ILWU ought to

have been permitted to raise a work-preservation defense to

SSA’s section 8(b)(4)(D) charge against ILWU.

Confusingly, two different doctrines both called the “work-

preservation defense” are potentially relevant here.

The first, which we have already discussed, is described

in the Supreme Court’s decision in ILA, 447 U.S. 490, and

typically applies to unfair labor practice charges under

section 8(b)(4)(B), 29 U.S.C. § 158(b)(4)(B). That work-

preservation defense draws a line between primary union

activity, which is permissible, and secondary union activity,

which is not. See National Woodwork Mfrs. Ass’n v. NLRB,

386 U.S. 612, 622–26 (1967) (explaining that, in drafting the

Act, Congress was particularly concerned with the evils of

secondary activity). Primary activity is aimed at a dispute

between an employer and its employees (or the union that

represents those employees). See Kinder Morgan, 978 F.3d

at 637. For example, a union engages in primary activity if

it pickets the premises of its members’ employer to induce

the employer to offer better terms to its members. Secondary

activity, by contrast, is directed at one employer but has the

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 13

goal of inducing that employer to take some action against a

third party with which the union has a dispute. See National

Woodwork, 386 U.S. at 622. For example, a union engages

in secondary activity if it pickets a construction site to

pressure the general contractor to fire its subcontractor

because that subcontractor has hired non-union workers. In

that scenario, the union exerts direct pressure on the general

contractor, who is presumably neutral in the dispute between

the union and the subcontractor, with the goal that the

general contractor will take some action against the

subcontractor.

To show that its conduct was primary, not secondary, a

union invoking the work-preservation defense must satisfy a

two-part test. First, the union must show that its conduct

“ha[d] as its objective the preservation of work traditionally

performed by employees represented by the union.” ILA,

447 U.S. at 504. “Second, the contracting employer must

have the power to give the employees the work in question.”

Id.

The Board argues that because the ILA work-

preservation defense exists to separate permissible primary

activity from impermissible secondary activity, it can be

invoked only when a union is alleged to have engaged in

secondary activity—that is, when a union is accused of

conducting a secondary boycott in violation of section

8(b)(4)(B). See 29 U.S.C. § 158(b)(4)(B). As the Board

explains, a pure jurisdictional dispute—which involves an

alleged violation of section 8(b)(4)(D)—necessarily does

not involve such allegations. That is because a jurisdictional

dispute is really an aggregation of two or more primary

disputes: Each union vying for the work has a contract

directly with the employer, and each union is attempting to

get that employer to take some action within the confines of

14 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

the employer-employee relationship. See International

Longshoremen’s & Warehousemen’s Union v. NLRB,

884 F.2d 1407, 1412–13 (D.C. Cir. 1989). Applying the ILA

work-preservation defense in that context would give every

union an automatic defense to section 8(b)(4)(D) charges,

gutting the Board’s section 10(k) authority to resolve

jurisdictional disputes.

Instead, the Board says, the only work-preservation

defense that applies here is the one articulated in the Board’s

decision in Highway Truck Drivers & Helpers, Local

107 (Safeway), 134 N.L.R.B. 1320 (1961). Under that

doctrine, a union can compel the Board to drop section

8(b)(4)(D) charges and quash notice of a section 10(k)

hearing if the union shows that the case is actually a “work

preservation dispute” between the employer and the union,

not a jurisdictional dispute between two unions. Id. at 1323.

To demonstrate that such a dispute exists, the union must

show that it previously performed the work at issue for that

employer (and therefore is not seeking to expand its work

jurisdiction) and that the employer precipitated the dispute

by unilaterally taking some action adverse to the union

(usually, by reassigning the work). See, e.g., Recon

Refractory & Const. Inc. v. NLRB, 424 F.3d 980, 990 (9th

Cir. 2005); Steel, Paper House, Chem. Drivers & Helpers

Loc. 578, 280 N.L.R.B. 818, 820 (1986). Unlike the ILA

work-preservation defense, the Safeway work-preservation

defense is not an affirmative defense; it is a way of showing

that a putative jurisdictional dispute is not a jurisdictional

dispute at all.

Because all parties to this case have conceded that it is a

classic jurisdictional dispute—and thus that it is not a work-

preservation dispute—they agree that the Safeway work-

preservation defense does not apply. The Board ascribes a

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 15

further consequence to that concession: The jurisdictional

nature of the dispute makes the ILA work-preservation

defense inapplicable, too. If we were writing on a blank

slate, we might find the Board’s argument persuasive. But

the Board’s argument is foreclosed by our decision in Kinder

Morgan.

Kinder Morgan involved a jurisdictional dispute

between ILWU and another union, the Electrical Workers,

over maintenance work at a marine terminal operated by

Kinder Morgan, a PMA-member employer. 978 F.3d at 628–

29. Kinder Morgan had historically subcontracted that work

“to a subcontractor which employed workers under its own

[collective-bargaining agreement] with the Electrical

Workers.” Id. at 631. When that arrangement persisted after

the PCLCD became effective and expanded the scope of the

longshoremen’s work, ILWU demanded the work for its

mechanics. See id. The Electrical Workers threatened to

picket the Kinder Morgan terminal, and Kinder Morgan

asked the Board to invoke section 10(k) to resolve the

dispute. See id.

The Board awarded the work to the Electrical Workers,

and ILWU continued to seek the work by pursuing grievance

procedures. See Kinder Morgan, 978 F.3d at 631–32. The

Board then filed an unfair labor practice charge against

ILWU under section 8(b)(4)(D) based on the grievance. See

id. at 632. ILWU invoked the work-preservation affirmative

defense, arguing that the grievance was intended to preserve

the work that it bargained for in the PCLCD and was directed

at the employer, Kinder Morgan, with the power to assign

the work. See id. The Board rejected that argument. See id.

at 632–33.

16 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

We reversed the Board’s order. See Kinder Morgan,

978 F.3d at 630. We held that “[a] valid work-preservation

objective provides a complete defense against alleged

violations of section 8(b)(4)(D), as well as against

jurisdictional disputes under section 10(k).” Id. at 637. Thus,

we explained, a union can avoid liability under section

8(b)(4)(D) by satisfying the two-part test outlined in ILA. See

id. at 637–38 (citing ILA, 447 U.S. at 504). And we

emphasized that the work-preservation defense can

accommodate situations in which a union has not historically

performed the precise work at issue but has bargained for the

work to preserve its traditional work patterns in the face of

technological changes that eliminated jobs. See id. at

638 (citing ILA, 447 U.S. at 506).

The Board’s conclusion that the ILA work-preservation

defense was inapplicable here cannot be reconciled with our

decision in Kinder Morgan. Both cases involve

jurisdictional disputes that the Board validly resolved under

its section 10(k) authority. In both cases, ILWU lost in the

section 10(k) proceedings and then attempted to undermine

the Board’s award in arbitration, which led the Board to

pursue unfair labor practices charges under section

8(b)(4)(D). In this case, ILWU fights that charge by pointing

to the same contractual entitlement to work that it pointed to

in Kinder Morgan. Having allowed it to do so there, we must

allow it to do so here.

The Board contests this conclusion on two grounds.

Neither is persuasive. First, it points out that Kinder Morgan,

unlike this case, involved allegations of secondary activity.

See 978 F.3d at 633 n.10. Specifically, the Board there

alleged that ILWU attempted to pressure Kinder Morgan to

cease doing business with the subcontractor that hired the

Electrical Workers rather than ILWU mechanics. See id. at

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 17

632. In the Board’s view, that secondary-activity allegation

made it appropriate for the court to permit ILWU to raise the

work-preservation defense, but the lack of a comparable

allegation makes it inappropriate here.

While the Board is correct that there was an allegation of

secondary activity in Kinder Morgan, that was not the only

allegation to which we held that the work-preservation

defense applied. To the contrary, we held that “[a] valid

work preservation objective provides a complete defense

against alleged violations of section 8(b)(4)(D), as well as

against jurisdictional disputes under section 10(k).” 978 F.3d

at 637. We made it clear that allegations of secondary

activity do not support charges under section 8(b)(4)(D), nor

do they give rise to disputes resolved under section 10(k). As

we noted in Kinder Morgan, the secondary-boycott

allegations there were brought under section 8(b)(4)(B). Id.

at 633 n.10. Thus, Kinder Morgan must mean that the ILA

work-preservation defense provides a “complete defense

against alleged violations of section 8(b)(4)(D)” in addition

to allegations of secondary activity brought under section

8(b)(4)(B). Id. at 637. It is for that reason that the court found

it unnecessary to “address [section 8(b)(4)(B)] separately”

when delineating the scope of the defense. See id. at 633

n.10.

Second, the Board suggests that our reading of Kinder

Morgan is in tension with our decision in Recon, 424 F.3d

980. That case involved a dispute between a construction

company, Recon, and a union, the Bricklayers. See id. at 981.

To reduce costs, Recon fired employees represented by the

Bricklayers and reassigned their work to employees

represented by another union, IPTW. See id. at 982. The

Bricklayers filed a grievance and a lawsuit for breach of

contract, and IPTW threatened economic action if Recon

18 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

reassigned the work to the Bricklayers. See id. at 984. Recon

asked the Board to resolve the dispute under section 10(k),

but the Board refused to do so because it found that Recon

had precipitated the dispute by unilaterally reassigning the

work to employees represented by IPTW. See id. at 985.

Citing Safeway, the Board found that the conflict was “not a

jurisdictional dispute suitable for resolution under § 10(k)”

but rather a “work preservation dispute” between Recon and

the Bricklayers that had to be resolved through arbitration.

See id. at 985; accord USCP-WESCO, 827 F.2d at 583. We

affirmed, describing the showing that the Bricklayers made

to avoid adjudication of the dispute under section 10(k) as

an invocation of “a work preservation defense.” Recon,

424 F.3d at 988–89 (quoting International All. of Theatrical

& Stage Emps., 337 N.L.R.B. 721, 723 (2002)).

But our decision in Recon did not say, as the Board

contends, that the Safeway work-preservation defense is the

only defense that is available when a union is alleged to have

violated section 8(b)(4)(D) in the context of a jurisdictional

dispute. Nor could it have—the Board’s finding that Recon

precipitated the dispute there meant that no genuine

jurisdictional dispute existed, and the Board declined to

enter a section 10(k) work award for that reason. See Recon,

424 F.3d at 985. The court in Recon had no occasion to

decide whether a union enmeshed in a genuine jurisdictional

dispute can rely on the ILA work-preservation defense to

avoid liability for conduct contravening an adverse section

10(k) award. That is the central question in this case, and

Kinder Morgan is the only decision from our circuit that

answers it.

In sum, Kinder Morgan compels us to hold that a union

charged with an unfair labor practice under section

8(b)(4)(D) may raise the ILA work-preservation defense

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 19

even when the union is not alleged to have engaged in illegal

secondary activity. The Board’s refusal to entertain the

work-preservation defense under Kinder Morgan was error,

so we remand to the Board to evaluate the merits of the

defense in the first instance. Because our conclusion that the

Board erred requires vacatur of the Board’s order, we do not

reach ILWU’s alternative argument that the underlying

section 10(k) work award was not supported by substantial

evidence. For the same reason, we also do not reach IAM’s

argument that the remedy required by the order was

insufficient.

* * *

ILWU’s petition for review (No. 23-632) and PMA’s

petition for review (No. 23-658) are granted; IAM’s petition

for review (No. 23-793) and the Board’s cross-petition for

enforcement (No. 23-780) are denied. Costs shall be taxed

against IAM in No. 23-793 and against the Board in Nos. 23-

632, 23-658, and 23-780.

VACATED and REMANDED.

MILLER, Circuit Judge, concurring:

I join the court’s opinion, which correctly applies our

decision in International Longshore and Warehouse Union

v. NLRB (Kinder Morgan), 978 F.3d 625 (9th Cir. 2020). I

write separately to express my view that Kinder Morgan was

wrongly decided. Kinder Morgan applies an affirmative

defense that the Supreme Court created to cabin the reach of

one statutory provision, section 8(b)(4)(B) of the National

Labor Relations Act, 29 U.S.C. § 158(b)(4)(B), to cases

arising under a separate statutory provision, section

20 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

8(b)(4)(D), id. § 158(b)(4)(D). It is not supported by

precedent; it creates a circuit conflict; and it undermines

Congress’s decision to empower the Board to resolve

jurisdictional disputes.

Under section 8(b)(4)(B), it is an unfair labor practice for

a union to “forc[e] or requir[e] any person . . . to cease doing

business with any other person.” 29 U.S.C. § 158(b)(4)(B).

Section 8(b)(4)(B) proscribes only secondary union activity;

it does not prohibit “any primary strike or primary

picketing.” Id.; see National Woodwork Mfrs. Ass’n v. NLRB,

386 U.S. 612, 620 (1967). That is, a union violates section

8(b)(4)(B) only when it attempts to prevail in a dispute with

one employer by involving another employer that is neutral

to that dispute. But if a union’s conduct is aimed at a dispute

within the employer-employee relationship—in other words,

if it is primary—the union does not violate section

8(b)(4)(B).

To distinguish between permissible primary conduct and

impermissible secondary conduct, the Supreme Court

developed the work-preservation defense. The defense

requires a two-part showing. First, the union’s conduct “must

have as its objective the preservation of work traditionally

performed by employees represented by the union.” NLRB v.

International Longshoremen’s Ass’n (ILA), 447 U.S. 490,

504 (1980). By focusing on work historically performed by

the union’s members, the first part of the test ensures that the

union is truly attempting to preserve existing work rather

than attempting to acquire new work. Second, the union

must show that “the contracting employer [has] the power to

give the employees the work in question.” Id. If the employer

does not have that power, “it is reasonable to infer that the

agreement has a secondary objective, that is, to influence

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 21

whoever does have such power over the work.” Id. at 504–

05.

Because the ILA work-preservation defense allows a

union to demonstrate that it did not act with an illegal

secondary objective, the Board has historically entertained

the defense only when a union is alleged to have engaged in

secondary activity in violation of section 8(b)(4)(B). See,

e.g., International Longshoremen’s Ass’n, 372 N.L.R.B. No.

36 (Dec. 16, 2022) (dismissing a section 8(b)(4)(B) charge

under the work-preservation defense); Teamsters Nat’l Auto.

Transporters Indus. Negotiating Comm., 335 N.L.R.B. 830,

832 (2001) (same). We have done the same. See, e.g.,

Associated Gen. Contractors of California, Inc. v. NLRB,

514 F.2d 433, 438 (9th Cir. 1975) (rejecting work-

preservation defense raised against section 8(b)(4)(B)

charges after determining that the union’s objective was

work acquisition).

That changed in Kinder Morgan. There, we held that the

ILA work-preservation defense can be raised “against

alleged violations of section 8(b)(4)(D),” in addition to

alleged violations of section 8(b)(4)(B). 978 F.3d at 637.

Section 8(b)(4)(D) addresses jurisdictional disputes, which

arise when two unions have valid contractual claims to the

same work and one or both of those unions seeks to secure

the work for its employees through means such as picketing.

Fearing the labor instability that jurisdictional disputes

generate, Congress directed the Board to resolve those

disputes through section 10(k), 29 U.S.C. § 160(k). See

NLRB. v. Radio & Television Broad. Eng’rs Union, 364 U.S.

573, 580 (1961). A section 10(k) work award is not

independently binding but is enforced through section

8(b)(4)(D). See NLRB v. Plasterers’ Loc. Union No. 79,

404 U.S. 116, 126–27 (1971). If the union that is not

22 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

awarded the work complies with the Board’s work award,

the initial section 8(b)(4)(D) charges will be dismissed. See

id. at 127. But if that union continues to pursue the disputed

work, a further section 8(b)(4)(D) complaint will issue, and

the union will likely be found guilty of an unfair labor

practice. See id.

In the context of section 8(b)(4)(D), the Board has

recognized a different (but confusingly similarly named)

work-preservation defense. See Highway Truck Drivers &

Helpers, Local 107 (Safeway), 134 N.L.R.B. 1320 (1961).

The Safeway work-preservation defense allows a union to

compel the Board to drop section 8(b)(4)(D) charges and

quash notice of a section 10(k) hearing if it can show that the

case is actually a work-preservation dispute between the

employer and the union, and not a jurisdictional dispute

between two unions. Id. at 1323. But it was never meant to

apply where, as here, two unions have a genuine

jurisdictional dispute.

Grafting the ILA work-preservation defense onto section

8(b)(4)(D), as Kinder Morgan did, undermines the

jurisdictional dispute-resolution scheme enacted by

Congress. The Board’s section 10(k) work award is effective

because of the prospect of a follow-on section 8(b)(4)(D)

charge. But a union entangled in a jurisdictional dispute now

has little reason to worry about that section 8(b)(4)(D)

charge because it will almost always be able to escape

section 8(b)(4)(D) liability by raising the work-preservation

defense that prevailed in Kinder Morgan. That is because

every jurisdictional dispute, by its nature, involves two

irreconcilable primary disputes—each one between the

employer who has the authority to control the work and a

union whose collective bargaining agreement seeks to

preserve the union’s work jurisdiction. See International

INT’L LONGSHORE & WAREHOUSE UNION V. NLRB 23

Longshoremen’s & Warehousemen’s Union v. NLRB (Sea-

Land), 884 F.2d 1407, 1408 (D.C. Cir. 1989). By providing

the disappointed union with a reliable affirmative defense to

the prospective section 8(b)(4)(D) charge, Kinder Morgan

renders the section 10(k) work award illusory by removing

the union’s incentive to comply with it.

No precedent supports that result. Kinder Morgan cited

several Supreme Court cases in support of its holding, but

each of those cases involved charges brought under section

8(b)(4)(B), not section 8(b)(4)(D). See National Woodwork,

386 U.S. at 644–46; ILA, 447 U.S. at 503–13; NLRB v.

International Longshoremen’s Ass’n, 473 U.S. 61, 79–82

(1985). And an affirmative defense available in the section

8(b)(4)(B) context should not be reflexively imported to the

section 8(b)(4)(D) context because “the theoretical bases for

each charge are different.” Sea-Land, 884 F.2d at 1412

(quoting International Longshoremen’s & Warehousemen’s

Union, Loc. 62-B v. NLRB, 781 F.2d 919, 922 (D.C. Cir.

1986)). Indeed, the only other circuit to have squarely

confronted this question concluded that the ILA work-

preservation defense does not immunize conduct charged

under section 8(b)(4)(D). See id. at 1410–13. In so holding,

the District of Columbia Circuit intimated what the facts

here make clear: Permitting a union to raise the work

preservation defense to a section 8(b)(4)(D) charge would

unravel the mechanism that Congress created to enable the

Board to resolve jurisdictional disputes. See id. at 1413.

Attempting to defend Kinder Morgan, ILWU argues that

allowing a union to raise the section 8(b)(4)(B) ILA work-

preservation defense to a section 8(b)(4)(D) charge fosters

labor peace by assuring contracting parties that their

negotiated compromises will be respected. The problem, of

course, is that while deference to contractual solutions may

24 INT’L LONGSHORE & WAREHOUSE UNION V. NLRB

be ILWU’s preferred method of ensuring labor peace, it was

not Congress’s. Congress concluded that jurisdictional

disputes should be resolved by the Board under its section

10(k) authority. And although Congress empowered the

Board to consider the parties’ collective bargaining

agreements in the section 10(k) hearing, it left to the Board

alone the task of weighing that factor against the other

relevant considerations. See International Ass’n of

Machinists, Lodge 1743, 135 N.L.R.B. 1402, 1405–10

(1962); 29 U.S.C. § 160(k).

As a three-judge panel, we are bound by Kinder Morgan,

which compels us to vacate the Board’s order. But the court

should reconsider it en banc.