Members of the United Auto Workers (UAW) union voted in favor of authorizing a strike at the Detroit Three automakers if an agreement over a new contract is not reached before the current one expires on Sept. 14, UAW President Shawn Fain said on Friday.

The development comes as the union and the companies - General Motors, Ford Motor and Stellantis - made little progress in their talks for a new labor deal.

Analysts estimate there is more than a 50% chance of a strike.

Fain, who presides over the union that represents about 150,000 workers at the automakers, said 97% of voting members approved the strike authorization, which is seen as a leverage to enhance pay talks.

While strike authorization votes are a common bargaining tool in the U.S. auto sector and other industries, the tension surrounding this year's contract talks in Detroit is new.

The announcement comes as labor unions are taking advantage of low unemployment to push for higher pay and better working conditions in their talks for new labor agreements.

Fain told Reuters on Aug. 17 that the automakers were "still not serious" in their responses to the union's economic proposals.

He has outlined an ambitious set of goals, including ending the tiered wage system that pays new hires less than veterans, reinstating cost-of-living adjustments and restoring defined-benefit pension plans that the automakers ended years ago for new hires.

GM, Ford and Stellantis have said they want to reach a deal that is fair to the workers but also gives the companies flexibility, as the industry shifts to electric models that have fewer parts and require less labor.

(Reporting by Shivansh Tiwary in Bengaluru; Editing by Arun Koyyur)