Will Bernie Sanders' proposed 32-hour workweek pass Congress?

A push to slash the standard workweek from 40 hours to 32 achieved a breakthrough this week, gaining a foothold in the Senate with a proposal that would require businesses to offer the 32-hour workweek but preserve employee pay.

The bill, put forward by Sen. Bernie Sanders, I-Vt., drew praise from labor advocates who tout the benefits of the reduced hours not only for workers' wellbeing but for the productivity benefits enjoyed by their employers.

However, political analysts who spoke to ABC News cast doubt on the measure's chances of passage in a divided Congress where opposition from Republicans is all but certain and even the extent of support among Democrats remains unclear.

"It's so hard to get anything passed, especially when you have such high levels of polarization. It doesn't take a lot to stop legislation," Richard Hall, a professor of political science at the University of Michigan, told ABC News.

"You'd have to imagine a very different political world than what we have now," Hall added.

Proponents of the measure point to the output gains generated by workplace technology, including recent improvements in automation and artificial intelligence.

The standard 40-hour workweek became a federal requirement in 1940, when rudimentary machinery made for diminished worker productivity. Today, much more output can be achieved in fewer hours, advocates say.

A study out of the United Kingdom last month found nearly 9 in 10 companies opted to retain a four-day workweek after participating in a temporary pilot program.

Support for the measure in Congress, however, remains scant. The proposal made by Sanders on Wednesday carries the support of just two other lawmakers, California Democrats Sen. Laphonza Butler and Rep. Mark Takano.

"I don't see this current iteration of the law getting through Congress," Lynne Vincent, a professor of industrial and labor relations at Syracuse University, told ABC News.

A near-identical bill proposed by Takano in the House last year gained the support of just seven colleagues in that chamber.

Some Republican lawmakers voiced opposition to the newly announced measure in a hearing of the Senate Committee on Health, Education, Labor and Pensions on Thursday.

The proposal amounts to an effective pay increase forced upon businesses, Sen. Bill Cassidy, R-La., said, predicting that the 32-hour workweek would "destroy some employers."

"They would ship those jobs overseas or they would automate to replace those workers for whom they have an increased expense, or they would dramatically increase prices to stay afloat," Cassidy added.

Sen. Mike Braun, R-In., said a 32-hour workweek could be appropriate as a voluntary policy adopted by some large businesses, but he expressed strong opposition to a federal requirement.

"I disagree with trying to do anything from this place that would impose upon the preponderance of businesses out there where I just don't think they could survive," Braun said.

The push for a shortened workweek has gained momentum in recent years, driven in part by the rise of employee flexibility during the COVID-19 pandemic.

Spain, Iceland and South Africa are among the nations that have implemented a trial of the four-day workweek for select companies and workers.

Belgium enacted a law in 2022 that requires employers to offer full-time workers a right to request a four-day workweek.

At the state level, lawmakers in Massachusetts introduced a bill last year that would provide employers with a tax credit if they shift at least 15 workers to four days a week without cutting their pay.

In California, lawmakers have introduced a bill that would set the standard workweek at 32 hours.

"Reducing the number of working days is not a new idea," Vincent said. "We have evidence from different sectors and countries that this can work."

Still, Vincent added, the measure stands little chance of passage under the current Congress. "Whenever there's anything related to a large change, it's going to meet a lot of resistance," Vincent said.

For the bill to reach President Joe Biden's desk, it would need to garner majority support in the Republican-controlled House as well as a filibuster-proof 60 vote approval in the Senate. If the measure were to reach Biden, it remains unclear whether he would sign it.

"It will never get through Congress -- not in my lifetime," Tracy Roof, a professor of political science at the University of Richmond who focuses on labor issues, told ABC News. "Maybe it will happen in my children's lifetimes."

-ABC News' Leah Sarnoff contributed to this report.