(DETROIT) — A four-day workweek at full-time pay, a 46% wage increase and a share of company profits are among the demands of the union representing approximately 150,000 workers at the Big 3 U.S. automakers — General Motors, Ford and Stellantis.

The United Auto Workers, or UAW, has vowed to launch a strike on Sept. 14 if the union and the automakers fail to reach an agreement by then.

Even UAW President Shawn Fain last month described the workers’ set of demands as “audacious.” He has defended the ambitious agenda in a series of public statements, citing billions in profits enjoyed by the Big 3.

The automakers, meanwhile, have largely rejected the demands. Only Ford has presented a contract proposal, offering a 9% wage increase over the term of the contract, plus a one-time payout that brings the total raise to 15%.

“Overall, this offer is significantly better than what we estimate workers earn at Tesla and foreign automakers operating in the U.S.,” Ford President and CEO Jim Farley said in a statement on Thursday.

Ford and General Motors declined to respond to ABC News’ request for comment.

In a statement, Stellantis told ABC News that discussions with the union’s bargaining team “continue to be constructive and collaborative with a focus on reaching a new agreement that balances the concerns of our 43,000 employees with our vision for the future — one that better positions the business to meet the challenges of the U.S. marketplace and secures the future for all of our employees, their families and our company.”

Meanwhile, Ford said it looks “forward to working with the UAW on creative solutions during this time when our dramatically changing industry needs a skilled and competitive workforce more than ever.”

In a statement on Thursday, General Motors Executive Vice President, Global Manufacturing, Gerald Johnson said: “The pace of negotiations is based on how quickly both parties resolve nearly 1,000 UAW demands, including more than 90 presented this week. Our goal remains the same — to achieve an agreement without a disruption that rewards our team members and protects the future of the entire GM team.”

As a potential strike approaches, here are some key UAW demands and what to know about them:

46% wage increase

The UAW has called for a 46% pay increase over the duration of a four-year contract, increasing top hourly wages to about $47 per hour.

Offering context for the extent of the pay increase, Fain has cited recent compensation increases for CEOs at the Big 3 as well as elevated inflation that has cut into purchasing power of workers.

“We went to Ford and proposed a double-digit wage increase, just like the Big 3 CEOs have received over the last four years,” Fain said on Facebook Live on Thursday. “Because we know our members are worth the same and more.”

“We also have a lot to make up for. In inflation adjusted dollars, our starting pay today is $10 an hour less than what it was in 2007,” Fain added.

In response, Ford said that full-time employees would be well-compensated under its offer of a 9% wage increase over the term of the contract, plus a one-time payout that brings the total raise to 15%.

“Full-time permanent Ford employees at the top wage rate could be paid $98,000 – from wages, cost-of-living adjustment bonus, ratification bonus, profit sharing and overtime – in the first year alone,” Farley said in a statement on Thursday.

32-hour workweek

One of the most eye-catching demands put forward by the UAW is a call for a 32-hour workweek at full-time pay.

The request arrives at a time when a growing roster of companies use a four-day workweek, fueling a movement that has accelerated amid a pandemic-era reconsideration of the workplace, experts previously told ABC News.

“We need to get back to fighting for a vision of society in which everyone earns family-sustaining wages and everyone has enough free time to enjoy their lives and see their kids grow up and their parents grow old,” Fain said.

The counteroffer from Ford appears to preserve a five-day workweek. In addition, it keeps benefits such as paid vacation and family days at current levels set under a contract reached in 2019.

Under that deal, full-time permanent employees could reach a maximum of five weeks of paid vacation annually as well as two family days.

“We are committed to creating opportunity for every UAW worker to build a great career at Ford and to become a full-time permanent Ford employee with the good middle-class wages and benefits that come with it,” Farley said.

Protections for workers if their plant closes

In addition to other reforms, the UAW has sought assurance that workers will keep getting paid if their manufacturing plant gets closed.

On top of that, the union has sought the right to strike in the event of a plant closure, giving such workers a source of leverage as the company winds down production.

“The Big 3 want the power to take our jobs and the products we build and move them to other countries where they can more easily exploit workers,” Fain said. “That results in massive job loss that guts local economies and rips apart families as workers uproot themselves from their lives and homes to travel across the country to get another job.”

Farley did not address this specific issue in a statement on Thursday but he emphasized the importance of Ford remaining competitive with other automakers.

“We will not make a deal that endangers our ability to invest, grow and share profits with our employees,” Farley said. “That would mortgage our future and would be harmful to everyone with a stake in Ford, including our valued UAW workers.”

ABC News’ Meredith Deliso contributed reporting.

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