By Daniel Wiessner

Oct 16 (Reuters) - The National Labor Relations Board has sued California to block a law that channels private-sector labor disputes to a state board while the federal agency is shorthanded and cannot decide cases, echoing the NLRB's pending challenge to a similar law in New York.

The board's lawsuit filed Wednesday in Sacramento federal court says the law, approved last month by Governor Gavin Newsom, a Democrat, unlawfully usurps the NLRB's exclusive authority to regulate private-sector labor relations nationwide.

"This encroachment disrupts the balance of federal and state powers," board lawyers wrote.

The office of California Attorney General Rob Bonta, a Democrat, did not immediately respond to a request for comment on Thursday.

Lawmakers in New York and California passed the laws after President Donald Trump, a Republican, fired Democratic NLRB Member Gwynne Wilcox in an unprecedented move in January, which left the board without the three members necessary to rule in individual cases. Wilcox has sued, and her removal was upheld by the U.S. Supreme Court pending the outcome of her case.

The NLRB and Amazon.com last month filed separate lawsuits claiming that New York's law is preempted by the federal National Labor Relations Act. Their requests to block the law from being enforced pending the outcome of the cases are pending.

The NLRB's loss of a quorum has put hundreds of NLRB cases in limbo, including dozens in which employers have appealed unions' election victories to a board that cannot decide them.

The NLRB's acting general counsel – Trump appointee William Cowen – has said that only a small fraction of cases ever reach the five-member board and that the agency's work has been largely unaffected by the absence of a quorum.

California and New York's laws authorize agencies that typically hear labor disputes involving state and local government employees to take up private-sector cases normally reserved for the NLRB when the federal board cannot function.

Newsom, New York Governor Kathy Hochul and other Democrats have said the laws are necessary to ensure that workers can continue to exercise their rights to advocate for better working conditions, join unions and collectively bargain.

But the NLRB, in its lawsuit against California, said allowing states to assert jurisdiction over private-sector employers threatens to destabilize labor relations by creating a nationwide patchwork of potentially conflicting standards.

The case was assigned to U.S. District Judge Troy Nunley, an appointee of Democratic former President Barack Obama. The judges hearing the New York cases were appointed by Trump and Republican former President George W. Bush.

Trump has nominated James Murphy, a retired career NLRB staffer, and Boeing chief labor counsel Scott Mayer for seats on the board. But a U.S. Senate committee last week scrapped a planned vote on Mayer's nomination after he clashed with Senator Josh Hawley, a Republican from Missouri, during a hearing.

The Republican-led committee approved the nomination of Murphy and of Morgan Lewis & Bockius partner Crystal Carey to serve as NLRB general counsel, setting up confirmation votes by the full Senate.

The case is NLRB v. California, U.S. District Court for the Eastern District of California, No. 2:25-cv-02979.

For the NLRB: Nancy Kessler Platt, Dawn Goldstein, and Chad Wallace

For the state: The California Attorney General's office

Read more:

Amazon sues to block New York state labor law

NLRB official warns states against moving to regulate labor relations

Trump paralyzes US labor board by firing Democratic member

US Supreme Court lets Trump keep labor board members sidelined for now

Frozen feud: How Trump and the Supreme Court helped put historic Whole Foods union bid on ice

US Senate panel approves two Trump NLRB nominees, tables a third

US senators question independence of Trump's NLRB picks after member's firing

(Reporting by Daniel Wiessner in Albany, New York)

((daniel.wiessner@thomsonreuters.com))