The United Auto Workers union said on Thursday it filed unfair labor practice charges against Volkswagen , as the automaker cut jobs at a factory in Tennessee where the union is negotiating its first contract after winning an election there last year.

Last year, the majority of employees at VW’s factory in Chattanooga, Tennessee, voted to join the United Auto Workers (UAW) union, but as the UAW negotiates its first contract with the automaker, it accused VW of unfair labor practices.

VW is cutting back to two shifts producing the electric VW ID Buzz, which is being built at the first foreign-owned Southern auto plant to unionize.

Volkswagen cuts a shift at its Tennessee plant amid EV demand struggles, sparking a UAW unfair practices claim.