Amazon’s Whole Foods says Trump’s firings that paralyzed a federal labor regulator invalidate a union vote at a Philadelphia store.

In a filing with the NLRB, the Amazon-owned retailer accuses the union of interfering with the vote. The union called the allegations baseless, legal maneuvering to delay bargaining.

A majority of workers at a Whole Foods Market in Philadelphia voted in favor of joining the United Food and Commercial Workers International union, presenting a new foothold for organized labor within parent-company Amazon.

Whole Foods workers in a Pennsylvania store vote to form the first union under Amazon ownership, joining a local chapter of the UFCW.