Members of the United Auto Workers (UAW) Local 230 and their supporters walk the picket line in front of the Chrysler Corporate Parts Division in Ontario, California, on September 26, 2023, to show solidarity for the "Big Three" autoworkers on strike
Members of the United Auto Workers (UAW) Local 230 and their supporters walk the picket line in front of the Chrysler Corporate Parts Division in Ontario, California, on September 26, 2023, to show solidarity for the "Big Three" autoworkers on strike AFP

Members of the United Auto Workers (UAW) have ratified the in-principle labor agreements promising sweeping pay increases that were reached with US car companies Ford, Stellantis and General Motors, a union source told AFP Saturday.

"All three are ratified," the source said of the agreements, which were reached after an unprecedented strike that lasted more than six weeks.

According to information published on the union's website Thursday, around 55 percent of hourly staff at GM voted in favor the four-year contract.

At Ford, 67 percent of unionized employees voted in favor of their contract, while nearly 69 percent voted in favor at Stellantis, according to the UAW website Saturday.

Stellantis, which owns the Jeep and Chrysler brands, confirmed the ratification in a statement.

"With negotiations now officially behind us, we will focus our full attention on executing our Dare Forward 2030 strategic plan and serving our customers by delivering the high-quality products and technologies they want and expect," North America COO Mark Stewart said in a statement.

Neither Ford nor the UAW immediately responded to AFP's request for comment on Saturday.

The strike came after UAW president Shawn Fain, who was elected in the spring, targeted Detroit's "Big Three" all at once for the first time in the organization's 90-year history.

It began with three factories employing nearly 13,000 people in mid-September, before the walkouts spread to more sites and eventually saw 45,000 of the UAW's 146,000 "Big Three" members downing tools.

The striking workers returned to work after the agreements-in-principle were announced, rather than following the usual process of waiting for their ratification.

The union had demanded a 40 percent salary increase over four years, to keep up with corporate compensation over the same period.

During the negotiation period, Fain repeated his rallying cry, "Record profits mean record contracts."

The final agreements allow for a 25 percent base salary increase over four years, cost of living adjustments, increased benefits and improved contracts for retirees, among other measures.

Each of the three contracts also include specific language for each company, such as measures on employment terms at Stellantis and the cancellation of a plan to close a GM factory in Illinois.

Joe Biden -- who became the first modern US president to join a picket line by visiting striking UAW workers and has made union support a key element of his 2024 re-election campaign -- posted a pro-labor message to social media Saturday afternoon as news of the ratifications spread.

"I'm proud to be the most pro-union president in American history," he posted on X, formerly Twitter, saying his likely White House opponent Donald Trump "attacks unions," while Biden "stands with unions."