Workers at the General Motors Fairfax plant in Kansas City, Kan., voted overwhelmingly to authorize a strike.

The vote on Thursday does not mean the workers will go on strike. It gives those bargaining for the union the authority to call for a strike if negotiations break down.

KSHB-TV reports that more than 90% of those who voted approved authorizing the strike. Workers said the main point of contention is the possible loss of seniority rights.

The vote was called after workers rejected a new local union contract. The plant has more than 4,000 workers.

Fairfax manufactures the Chevy Malibu, which was the company’s second-best selling car in the U.S. last year.