The Paycheck Protection Program is set to expire at the end of the month — and while the House has already passed a bill to extend the program, the Senate has not taken it up yet. The upper chamber is expected to consider the extension this week.

The House bill would allow business owners to apply for the forgivable loans through May 31, instead of March 31, and give the Small Business Administration until June 30 to process the loans.

Sen. Marco Rubio (R., Fla.) told Yahoo Finance he believes Congress will extend the program before the end of the month, but he would like to see some changes to the House bill. If the Senate were to tweak the bill, the House would have to take it up again.

"I don't want us to punish, you know, some small business out there that needs the help because of a political fight over here," said Rubio in an interview.

Earlier this month, Rubio and several other Republican senators introduced a bill to extend the program and prohibit the SBA from prioritizing some applicants over others. Rubio's office said he plans to introduce the bill as an amendment to the House-passed extension.

There have been increased calls to extend the program after President Biden changed the rules of the program — making sole proprietors eligible for more money, granting a two-week application window specifically for the smallest businesses, and ensuring eligibility for small-business owners with delinquent student loans, non-citizen business owners who are lawful U.S. residents and business owners who have non-fraud felony convictions.

Rubio told Yahoo Finance he's concerned about the administration making changes to the program without involving Congress.

"What that begins to do is it begins to create partisan fissures... for a program that's had bipartisan support," said Rubio. "If you add to that eligibility criteria outside of what Congress intended, you're going to run out of money."

The goal of the Biden administration's changes was to make sure the neediest businesses were able to access the relief. However, the new loan calculation formula for sole proprietors has caused some problems and confusion. Sole proprietors who now qualify for larger loans worry they won't have time to take advantage of the change before the March 31 deadline.

Sen. Ben Cardin (D., Md.), chairman of the Senate Small Business Committee, told reporters on Wednesday he's also optimistic the program will be extended.

"I think we'll get it done," he said.

"Common sense here tells you, you don't punish thousands of businesses because of, you know, one or two bad actors," Rubio said. "I think that's true when it comes to the fraud and the program, which clearly existed. And I think it's true when it comes to these political flashpoints."

Jessica Smith is chief political correspondent for Yahoo Finance, based in Washington, D.C. Follow her on Twitter at @JessicaASmith8.

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