Robert Brown|UAW strike day 4: GM threatens to send 2,000 workers home, Ford cuts 600 jobs

As the auto workers' strike enters day 4,Robert Brown the two sides are digging in.

On one side are the United Auto Workers who say record corporate profits should yield a record contract.

"If we don't get better offers... then we're going to have to amp this thing up even more," warned UAW President Shawn Fain on CBS's Face Of The Nation.

On the other, are the Big three automakers — General Motors, Ford and Stellantis — who say they have put historically generous offers on the table, while also emphasizing that there are limits.

"Our goal is to secure a sustainable future that provides all our UAW-represented employees with an opportunity to thrive in a company that will be competitive during the automotive industry's historic transformation," Stellantis said in a statement.

Talks have continued over the weekend with no end in sight. And the ripple effects have already started.

Workers are out of jobs and companies won't pay them

Ford told 600 workers not to report to work at its Michigan Assembly Plant's body construction department because the metal parts they make need to be coated promptly for protection and the paint shop is on strike.

General Motors warned that 2,000 workers are expected to be out of work at its Fairfax Assembly plant in Kansas this coming week. The company says that's due to a shortage of critical materials supplied by the stamping operations at its Wentzville plant in Missouri.

The historic strike kicked off right after the stroke of midnight on Friday morning with 9% of the UAW's nearly 150,000 union members walking off their jobs. The three auto plants — a General Motors assembly plant in Wentzville, Mo., a Stellantis assembly plant in Toledo, Ohio, and part of a Ford plant in Wayne, Mich. — were the first join the picket lines.

Normally companies give partial pay to workers when a plant is idled.

But because in this case it's due to a strike, the companies say there is no such compensation. General Motors said in a statement, "We are working under an expired agreement at Fairfax. Unfortunately, there are no provisions that allow for company-provided SUB-pay in this circumstance."

The UAW says it will make sure that affected workers don't go without an income.

Here's the latest.

• Union strategy: 13,000 auto workers at the three Midwest plants, about 9% of the unionized workforce at the Big Three automakers, were the first to walk off the job. Now more workers are temporarily out of work as the automakers are asking hundreds of non-striking workers not to show up to work.
• Negotiation and demands: The UAW's call for a 40% pay increase is still intact as negotiations continue. Also on the docket are pensions, cost of living adjustments and quality of life improvements.
• Reactions: President Biden urged automakers to share their profits with workers as the strike tested his bid to be the "most pro-labor" president. He has dispatched Julie Su, the acting labor secretary, and Gene Sperling, a White House senior adviser, to head to Detroit to help with negotiations.

So far, both sides aren't making much progress, according to the union.

"Progress is slow, and I don't really want to say we're closer," Fain told MSNBC on Sunday morning.

Fain said they plan to continue negotiations Monday.