Congressional hardliners on the left and right are uniting in opposition to talks of saving a controversial surveillance tool of the U.S. government by linking it to an annual must-pass military and defense bill. 

The House of Representatives is no stranger to public division, but it’s rare for issues to unite progressives and conservatives like this. 

Section 702 of the Foreign Intelligence Surveillance Act (FISA) has been both credited with preventing terror attacks on U.S. soil and accused of being a vehicle for spying on U.S. citizens. 

It lets the government keep tabs on specific foreign nationals outside the country without first obtaining a warrant to do so, even if the party on the other side of those communications is an American on U.S. soil.

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Chip Roy, pramila jayapal

Conservatives including Rep. Chip Roy, R-Texas, and progressives including Rep. Pramila Jayapal, D-Wash., are united in opposing a "clean" FISA extension (Getty Images)

The program expires at the end of this year if not reauthorized. Multiple sources told Fox News Digital that congressional leaders are discussing punting that fight until early 2024 by attaching a temporary extension of FISA to the National Defense Authorization Act (NDAA).

The NDAA is an annual bill laying out priorities for the Pentagon and other U.S. defense programs.

Freedom Caucus Policy Chair Rep. Chip Roy, R-Texas, told Fox News Digital that he believes that combining the two would ensure the least conservative of each was passed.

"They want to use clean FISA, which I oppose. But a thirty- to sixty-day extension of FISA while we negotiate reforms, not the end of the world if it's standalone, right? Because then it's kind of staying on its own merit. I can vote no, maybe it passes," Roy explained.

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The FBI used FISA to investigate Americans more than 278,000 times in 2021, including January 6 protesters and George Floyd demonstrators. (Getty Images)

"But if you take FISA and you add it to the NDAA, and we know that the NDAA is going to be stripped of our fixes on our side on abortion tourism, transgender surgeries, DEI, critical race theory…you're using the fear of the security of this country under FISA collection of data, and you're using that extension to pass a crap NDAA bill," Roy continued.

Critics of FISA on both the right and have claimed it encroaches on Americans’ civil liberties, specifically if the FBI conducts warrantless surveillance on communications between Americans and foreign nationals.

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A letter objecting to combining the measures was signed by more than 50 lawmakers on Wednesday, led by Reps. Warren Davidson, R-Ohio, and Andy Biggs, R-Ariz., members of the conservative House Freedom Caucus, along with Rep. Zoe Lofgren, D-Calif., and Progressive Caucus Chair Pramila Jayapal, D-Wash.

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More than 50 Republicans and Democrats wrote a letter to Speaker Mike Johnson urging him not to link a FISA extension to the NDAA. (AP Photo/J. Scott Applewhite)

"A temporary extension would be entirely unnecessary, and it would be an inexcusable violation of the public’s trust to quietly greenlight an authority that has been flagrantly abused," the letter addressed to Speaker Mike Johnson, R-La., said.

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"If Section 702 is to be reauthorized for even a single day, it must be through standalone legislation subject to robust, open debate and amendment."

Fox News Digital reached out to Speaker Mike Johnson's office to confirm the discussions but did not immediately hear back.