Donald Trump will attempt to woo blue-collar workers in Michigan in an intensifying political tug-of-war with Joe Biden a day after the sitting president visited a picket line to declare support for a trade union strike against the US’s three flagship carmakers.

Targeting working-class voters in the key battleground, the former president will attempt to upstage Tuesday’s appeal by Biden to union members on the frontline of the United Auto Workers (UAW) strike, which is turning into a proxy struggle for next year’s presidential election.

Trump will address about 500 workers, including UAW members, at Drake Enterprises, a non-unionised car parts maker in Macomb county, a few miles from where Biden spoke to striking employees picketing a Ford facility.

Wednesday’s speech is timed to coincide with the second Republican primary debate at the Ronald Reagan library in Sima Valley, California, which Trump is avoiding to cement his self-anointed status as the party’s presidential candidate-in-waiting. Seven Republican candidates, all of them trailing Trump by wide margins in opinion surveys, will take part in the debate.

Trump has emitted a sympathetic feeling towards workers striking against Ford, General Motors and Stellantis without explicitly endorsing their demands for a 40% pay rise, shorter working hours and better pensions – which polls show a majority of Americans support.

Instead, he has accused the UAW’s leadership of selling its members “down the river” and attacked Biden’s clean energy policy of incentivizing the three car giants to convert to manufacturing electric vehicles.

“REMEMBER, HE [Biden] WANTS TO TAKE YOUR JOBS AWAY AND GIVE THEM TO CHINA AND OTHER FOREIGN COUNTRIES,” Trump wrote on his Truth Social site. “I WILL KEEP YOUR JOBS AND MAKE YOU RICH.”

Shawn Fain, the UAW president, who stood beside Biden on Tuesday after inviting him to join the picket line despite having so far withheld his union’s endorsement of the president’s re-election bid, has unequivocally dismissed Trump’s efforts at drumming up union support.

“Every fibre of our union is being poured into fighting the billionaire class and an economy that enriches people like Donald Trump at the expense of workers,” he said when the strike started on 15 September.

“We can’t keep electing billionaires and millionaires that don’t have any understanding of what it is like to live paycheck to paycheck and struggle to get by and expecting them to solve the problems of the working class.”

But Trump has a track record of winning electoral support among union members – despite implementing a tax cut as president in 2017 that was overwhelmingly viewed as favoring the rich and corporate America.

He narrowly won Michigan, seen as a must-win state in the 2024 race, in 2016 before losing it in his defeat to Biden in 2020.

“Nowadays, social issues seem to move union members as much as anything and posturing works, as Trump has proved,” said Larry Sabato, a politics professor at the University of Virginia in Charlottesville. “Just playing the tough guy, the way Trump does, excites labour union members in many states. He isn’t going to win an outright majority of blue-collar workers, but he could persuade enough of them to repeat the success he had in 2016 in the right sort of circumstances – and they won’t be particularly influenced by criminal convictions.”