DETROIT (AP) — With about three weeks until contracts expire with Detroit's three automakers, the head of the United Auto Workers union says bargaining isn't going well.

President Shawn Fain told workers outside a Detroit factory that their walk Wednesday to practice picketing would become reality if General Motors, Ford and Stellantis don't start negotiating seriously.

"These companies better come to the table. The clock is ticking,” Fain told about 100 workers gathered in a parking lot near Stellantis’ Mack Avenue assembly complex. “Today I want you guys to have some fun practicing for what we’re going to have to do if these companies don’t give us our fair share.”

Contracts between the union representing about 146,000 workers at the companies expire at 11:59 p.m. on Sept. 14. Members are voting this week on whether to give union leaders authorization to call a strike.

The union is seeking a 40% pay increase, restoration of pensions for new hires, elimination of wage tiers and other items. Fain has often told workers they have to be ready to strike in order to achieve gains from the profitable automakers.

In a short interview with The Associated Press Fain characterized bargaining as slow. “We're not getting real far so far,” he said, but added that a strike is not inevitable.

Stellantis wouldn't comment Wednesday and referred to previous statements saying the company wants to fairly compensate workers and find solutions to protect Stellantis from nonunion companies with lower costs, and additional costs from moving to electric vehicles.

GM and Ford each have said they're bargaining in good faith.