DETROIT (AP) — The United Auto Workers union has turned up the heat on General Motors as 5,000 workers walked off their jobs Tuesday at a highly profitable SUV factory in Arlington, Texas.

The move comes just a day after the union went on strike at Stellantis’ pickup truck factory in Sterling Heights, Michigan, north of Detroit.

The Texas strike brings the total of UAW members that have walked off their jobs to 46,000 in a series of strikes that is entering its sixth week.

UAW President Shawn Fain last week threatened further strikes to get GM, Ford and Stellantis to increase their pay offers.

But GM CEO Mary Barra said on Tuesday morning’s earnings conference call that the company already has made a record offer and won’t agree to a contract that jeopardizes the company’s future.

“We are disappointed by the escalation of this unnecessary and irresponsible strike,” General Motors said in a statement Tuesday afternoon. “It is harming our team members who are sacrificing their livelihoods and having negative ripple effects on our dealers, suppliers and the communities that rely on us.

“Last week, we provided a comprehensive offer to the UAW that increased the already substantial and historic offers we have made by approximately 25% in total value. It is time for us to finish this process, get our team members back to work and get on with the business of making GM the company that will win and provide great jobs in the U.S. for our people for decades to come.”