If you take the Fairfax Connector bus in Virginia, you might have to consider alternate transportation Thursday.

More than 600 Fairfax Connector bus operators and mechanics are on strike against contractor Transdev over unfair labor practices.

The union — ATU Local 689 — says they’ve been working under an expired contract since last year.

“The strike, at this point, the ball is in Transdev’s hands,” Ben Lynn, with ATU Local 689, told WTOP.

Lynn said the union will be on strike “as long as necessary” to get a fair contract. They’re fighting for retirement security.

He says they expect the majority of Connector buses to be off the roads while the strike takes place.

“We did everything in our power to try to avert the strike,” Lynn said.

“We involved a mediator in the negotiation process. We’ve been consistently offering fair contract proposals, both fair to our members, the company and the public. And we’ve been trying to meet with Fairfax County officials, the Board of Supervisors.”

Fairfax Connector transports around 26,000 passengers daily.