Some senators are pushing to make changes to a House-passed bill that would extend a powerful surveillance authority for two years as differences persist over what privacy protections should be included to renew the program.

Senate Judiciary Chair Richard J. Durbin, D-Ill., and Sen. Kevin Cramer, R-N.D., filed an amendment that would install a warrant requirement for certain information collected under Section 702 of the Foreign Intelligence Surveillance Act.

And Sen. Ron Wyden, D-Ore., has called for a vote on an amendment he filed with Sen. Cynthia Lummis, R-Wyo., that would strip out a provision that his office called a “major expansion of warrantless surveillance.”

Majority Leader Charles E. Schumer, D-N.Y., said Friday morning in a floor speech that lawmakers were trying to see if there was a path to getting reauthorization legislation done quickly. But he said that “disagreements remain on how to proceed.”

“We want to get FISA done as soon as we can because it’s very important for our national security,” Schumer said. “But, as everyone knows, any one member can halt progress in this chamber, so both sides need to fully cooperate if we want to get FISA done.”

He then told his colleagues that members should be prepared to be there over the weekend if necessary. Without an agreement, the next procedural vote would be Friday night and a vote on final passage would not happen until next week.

The Section 702 authority allows the U.S. government to collect digital communications of foreigners located outside the country, but some senators have raised concerns that the program also sweeps up the communications of Americans and allows the FBI to search through data without a warrant.

Senate Minority Leader Mitch McConnell, R-Ky., said the House deserves credit for “reforming and reauthorizing” the surveillance authority and issued a dire warning if the Senate did not pass the legislation.

“Now, the Senate’s choice is clear. We can pass the House’s reform bill or, given the late hour and political reality, we can essentially doom the program to go dark,” he said. “Pass the House reform bill or give free rein to foreign intelligence operatives and terrorists to target America.”

The program expires Friday. But the Justice Department has told congressional leaders that the Foreign Intelligence Surveillance Court had taken action that would allow the program to continue to operate for up to a year even if it’s not reauthorized by April 19.

The Durbin amendment, according to a summary provided by his office, would require the U.S. government “to obtain a warrant from the Foreign Intelligence Surveillance Court (FISC) before reviewing the contents” of Americans’ communications.

The proposed change touches on a debate that sharply divided the House last week, when the chamber voted 212-212 to reject an amendment that would have added a different version of a warrant requirement to the program.

The Senate amendment is also being supported by Sens. Mike Lee, R-Utah, and Mazie K. Hirono, D-Hawaii.

On another issue, privacy advocates in recent days expressed alarm over an amendment that was included in the House-passed bill. They say the language would dramatically expand the scope of entities that would be compelled to help authorities under the program.

Under the bill, the law would include, with exceptions, “any other service provider who has access to equipment that is being or may be used to transmit or store wire or electronic communications.”

A Justice Department official, in a letter this week, argued that the provision includes “technical language” that modifies the definition of electronic communication service provider to address “unforeseen changes in electronic communications technology.”

“The technical modification is intended to fill a critical intelligence gap — which was the subject of litigation before the Foreign Intelligence Surveillance Court (FISC) — regarding the types of communications services used by non-U.S. persons outside the United States,” the letter read.

Wyden slammed the provision in a floor speech earlier this week, saying it would dramatically expand the government’s current authority to order entities to hand over communications.

He said supporters argue that the provision has a narrow purpose and that “the government doesn’t intend to start tapping into everybody’s phone line or Wi-Fi.”

“That’s not how this provision is written. It’s not reflected in the actual legislation,” Wyden said. “And I would say respectfully that anybody who votes to give the government vast powers under the premise that intelligence agencies won’t actually use it is being pretty darn naive.”

Nina Heller contributed to this report.