UNITED Auto Workers (UAW) members have back strike action against the big three US car-makers if agreement on a new contract is not reached by September 14.

The union said yesterday that a massive 97 per cent of members employed at General Motors, Stellantis (formerly Chrysler) and Ford had voted in favour of walkouts.

UAW president Shawn Fain, who was elected by the membership earlier this year, said: ”Ninety-seven per cent of you voted to authorise a strike because you know that we do have the power, that we are united and we’re not afraid and we’re gonna win. The Big Three’s race to the bottom ends on September 14.”

Mr Fain confirmed that the union would not agree to contract extensions and that the union would not select a target company on which to establish a pattern for an agreement.

“It is possible for us to get where we need to be,” Mr Fain said. “But these companies got to buckle down and get serious about your demands and about you getting your share of equity. We’ve got a lot to take care of in 20 days.”

Last year, General Motors, Stellantis and Ford reported adjusted operating income in North America of $13 billion (£10.3bn), $15.2bn (£12bn) and $9.2bn (£7.3bn) respectively.

 The union is demanding a 46 per cent wage rise over four years,  a 32-hour working week for 40-hours’ pay, defined benefit pensions and healthcare in retirement for all, increases in retired workers’ benefits, the right to strike over plant closures and more paid time off.

The UAW also wants an end to the two-tier wage structure agreed during the economic crisis of 2007, under which new recruits are paid at a lower rate than long-serving employees.

The companies have not yet commented on the union’s strike mandate.