Federal protections that have prevented millions of renters across the country from being evicted are about to expire and could leave them at risk of losing their homes if Congress does not act by Saturday.

Senate Democrats are urging an extension of the eviction protection program, but it is unlikely that a new coronavirus relief bill will make it across the finish line before the current protections lapse at the end of the week, as Republicans scramble to put their plan forward.

More than 12 million renters failed to make rent last month, according to data collected by the US Census Bureau for the week of July 9 through July 14. More than 23 million reported that they have slight or no confidence in their ability to make next month's rent.

"This is a potential catastrophe," Sen. Minority Leader Chuck Schumer said Wednesday. "Housing is fundamental."

Sen. Elizabeth Warren, D-Mass., blamed Republicans Wednesday for inaction on housing that she said has left the nation on the cusp of crisis.

"We are just days away from a housing crisis that could be prevented if Mitch McConnell stops stalling and the Senate acts," Warren said. "Failing to put a safeguard in place to keep people in their homes is most likely to harm the most vulnerable Americans.

Under the coronavirus relief legislation passed in March, renters who live in federally subsidized housing or in a property with a federally backed mortgage are currently protected from eviction. Landlords are not allowed to issue eviction notices until Saturday under the law, and late fees for missed rent following the passage of the law are prohibited. But if the legislation is not extended in the coming days, eviction notices for renters could follow.

Senate Majority Leader Mitch McConnell has not yet made clear whether the Republican proposal, which is expected to be introduced in the coming days, will include an extension of the eviction protection program, but on Wednesday several Republicans said they believed that the some sort of fix is going to be needed, though it's unclear what form it would take.

Sen. Rob Portman, R-Ohio, authored a bill alongside Democratic Sen. Michael Bennet of Colorado before the coronavirus pandemic which aimed to implement grant programs to prevent at-risk tenants from being evicted.

He said Wednesday that he'd like to see funding in the bill to address possible evictions that is "even broader" than what he proposed, though said he was unclear what form the legislation should take.

"I think its important that we deal with it, but again that's kind of a work in progress," Portman said "We should do it before next week because of the expiration."

Sen. Mike Crapo, who chairs the Senate Banking, Housing and Urban Affairs committee, said the form of eviction protection outlined in the next bill would be determined by other aspects of the legislation related to payments to Americans, like direct payments and unemployment insurance.

"We've got to work at the entire picture before we can describe exactly how any single piece will work," Crapo said.

Dr. Tim Thomas heads the Urban Displacement Project at University of California Berkley where he has researched evictions. He warned of possibly devastating impacts on vulnerable communities if rent protections do not continue.

"If this moratorium doesn't pass, you're going to have a lot of landlords that have not been paid in awhile and there's going to be a mass eviction," Thomas told ABC News.

He also warned that evictions could disproportionately impact communities of color. In his research on evictions he said he's found "just astronomical impacts on Black communities in particular."

Of those who said they had little or no confidence to make rent next month, 12 million were Hispanic or Black.