Wearing a United Auto Workers baseball cap, President Joe Biden told striking autoworkers on Tuesday that “unions built the middle class”, as he became the first sitting president to join a picket line.

UAW president Shawn Fain, who had invited Biden to join striking workers, thanked him for coming to the line outside a General Motors parts distribution centre in Belleville, Michigan, “to stand up, with us, in our generation’s defining moment”, before handing over a bullhorn to the US president.

“Wall Street didn’t build the country, the middle class built this country,” Biden told workers wearing red and waving signs. “And unions built the middle class?.?.?. You deserve what you’ve earned, and you’ve earned a hell of a lot more than you’re getting paid now.”