Sixth Circuit Raises Standard for NLRB Injunctions and Rejects Presumed Irreparable Harm

Takeaways

• The Sixth Circuit confirmed that the National Labor Relations Board must satisfy the full four-factor test under SCOTUS’s decision in Winter v. Nat. Res. Def. Council, rejecting any lower standard for 10(j) injunctions.
• A likelihood of success on the merits alone does not justify injunctive relief. Even where the Board is likely to prevail, failure to prove irreparable harm warrants denial of an injunction. 
• Courts may not presume or infer irreparable harm from an employer’s refusal to bargain. The Board must present concrete, non-speculative evidence showing that its remedial authority will be impaired absent interim relief.
• The decision raises the bar for 10(j) relief in the Sixth Circuit and provides employers stronger ground to challenge Board requests for interim injunctions.

Related link

• Kerwin, No. 24-1975 (6th Cir. May 1, 2026)
• U.S. Supreme Court Raises Standard for Labor Board When Seeking 10(j) Injunctions

Article

In its first opportunity to revisit its approach to Section 10(j) injunctions following the U.S. Supreme Court’s 2024 decision, the U.S. Court of Appeals for the Sixth Circuit rejected the circuit’s prior use of a less rigorous evidentiary standard. Kerwin, No. 24-1975 (6th Cir. May 1, 2026).

Background

An employee initiated a decertification election at a unionized Michigan hospital. Before officials announced the election results, the employer relied on a disaffection petition to withdraw recognition from the union. The election results ultimately reflected continuing majority support for the union, and the union then filed unfair labor practice charges with the National Labor Relations Board.

An administrative law judge determined that the employer unlawfully withdrew recognition, ruling it lacked credible evidence that the union had lost majority support. While that decision was pending before the Board, the Board regional director sought an injunction under Section 10(j) of the National Labor Relations Act, which the District Court granted and ordered the hospital to recognize and bargain with the union.

On appeal, the Sixth Circuit examined whether the District Court abused its discretion by applying the wrong legal standard, misapplying the correct one, or relying on clearly erroneous facts.

10(j) Injunctions

Section 10(j) allows the Board to seek preliminary injunctions in federal court to stop serious unfair labor practices while administrative proceedings are pending, authorizing courts to grant temporary relief as “just and proper.”

The Board pursued such relief sparingly in 2025, filing only nine petitions that year, according to the Board’s website.

Prior Standards and Supreme Court Remand

The Sixth Circuit previously applied a two-part test that permitted Section 10(j) injunctions upon a showing of “reasonable cause” that unfair labor practices had occurred and that relief was “just and proper.” McKinney v. Ozburn-Hessey Logistics, LLC, 875 F.3d 333, 339 (6th Cir. 2017).

In 2024, the Supreme Court rejected this approach as overly lenient, holding that courts reviewing 10(j) requests must apply the traditional four-factor preliminary injunction test articulated in Winter v. Nat. Res. Def. Council, Inc., 555 U.S. 7, 20 (2008). Under Winter, the Board must make a clear showing on each of the following factors:

1. It is likely to succeed on the merits;
2. It is likely to suffer irreparable harm in the absence of preliminary relief;
3. The balance of equities tips in its favor; and
4. An injunction is in the public interest.

Decision

Applying the Winter framework, the Sixth Circuit vacated the interim bargaining order. The court emphasized that Section 10(j) relief constituted an “extraordinary and drastic remedy” and held that the Board must satisfy the same four-factor standard as any other litigant seeking a preliminary injunction.

On the merits, the court agreed that the regional director was likely to succeed in establishing that the employer unlawfully withdrew recognition and refused to bargain. It found the disaffection petition contained significant defects and the employer lacked reliable “objective evidence” that the union had lost majority support at the time of withdrawal.

Despite the likelihood of success on the merits, the court reversed the injunction based on the absence of irreparable harm, which it described as indispensable to ordering preliminary relief. Although courts may consider future harm, the court rejected any presumption or inference favoring the Board. The court held that an employer’s refusal to bargain, standing alone, does not establish irreparable harm. It concluded the regional director’s evidence, consisting of equivocal union meeting attendance data and generalized employee concerns, failed to demonstrate the concrete and immediate harm required to justify extraordinary relief.

The court also concluded that the Board’s delay in seeking relief undermined any claim of urgency and further weighed against finding irreparable harm.

Practical Implications

The Sixth Circuit’s decision confirms that a traditional equity standard for evaluating the appropriateness of injunctive relief applies equally under Section 10(j) of the Act. The Sixth Circuit found that inferring irreparable harm in refusal-to-bargain cases is at odds with this standard. The ruling reflects reduced judicial deference to the Board’s statutory interpretations and evidentiary presumptions, with courts independently evaluating whether the record supports granting extraordinary relief.

For employers, the decision provides a more predictable standard and requires courts to consider and evaluate all prongs of the prevailing tests for equitable relief when considering Section10(j) injunction requests.

Although the Sixth Circuit panel recognized that some circuits permit district courts to infer irreparable harm in the context of alleged employer refusals to bargain, it expressly declined to adopt that approach or apply a less stringent standard when evaluating 10(j) petitions.

The Sixth Circuit has jurisdiction over Kentucky, Michigan, Ohio, and Tennessee.

Contact a Jackson Lewis attorney if you have any questions about this decision and its impact on preliminary injunctions.