Schisms are brewing on Capitol Hill over a new bipartisan effort to limit the authority and extend the timeline of the National Security Agency's ability to monitor the communications of suspected foreign agents abroad, as key members refuse to endorse the proposal.

The NSA data collection program under Section 702 of the Foreign Intelligence Surveillance Act has long inspired divisions between privacy advocates and national security hawks, over where and how collected data will be disseminated and used by various government agencies. But as lawmakers look toward a looming, end-of-year deadline to reauthorize the program, both privacy champions and advocates for the intelligence community are finding fault in the new House Judiciary Committee proposal. It requires the FBI to seek a warrant before asking to view Americans' emails and phone call records collected under Section 702 authority, relevant to criminal cases.

[Bipartisan group of lawmakers seeks to impose new curb on U.S. government spy power]

The disagreement is narrow, but critical to a Section 702 extension, which the intelligence community has identified as its top legislative priority for 2017.

In the House Judiciary Committee's bill, searches of the NSA database are unlimited in national security cases. But if the FBI wants to query the database for the communications of a U.S. person related to a criminal case, it must first seek a warrant before it can review the results.

The provision is inspired by concerns that with no restrictions on law enforcement officials' access to Americans' information in such a database, the FBI could exploit its contents to aid money-laundering investigations, tax fraud, murders, or other federal crimes without an explicit national security bent.

While Section 702 authority permits surveillance of foreign agents believed to be outside the United States, American citizens and U.S. residents can also end up being monitored if they are in communication with the target.

But the restriction is too great for the intelligence community and its advocates, who fear any limitation on their ability to search and review information contained in the database could negatively affect national security investigations.

[Spy agencies seek permanent authority for contested surveillance program]

The intelligence community is asking for a straight extension of the FBI's current, unfettered authority to query the database. It also wants that extension to be permanent.

House Intelligence Committee Chairman Devin Nunes (R-Calif.) said Thursday that it is likely to be impossible for Section 702 intelligence-gathering and querying authority to get through Congress without some limitations or changes, declining to endorse the ones in the House Judiciary Committee's bill.

In an interview Thursday, Intelligence Committee ranking Democrat Adam B. Schiff (Calif.) also said that some limitations to protect privacy and improve transparency would be necessary. But he disagreed with the House Judiciary Committee's approach of limiting searches, instead urging that if the concern was that information might be improperly used for criminal cases, it would be better to simply limit the admissibility of such communications as evidence in criminal court — much like evidence obtained through warrantless searches is often excluded.

"We want law enforcement and the intelligence community to be able to make queries of the database in a way that protect the country," he said. "If we're concerned about this vein turned into a grand database that can be used to prosecute people for unrelated things, then we ought to look more to excluding the use of the contents in nonnational security cases rather than preventing the searches from taking place."

It will not simply be left to officials of the House Judiciary and House Intelligence committees to iron out their differences on the front or back end. Sens. John Cornyn (R-Texas) and Dianne Feinstein (D-Calif.) — both of whom sit on both the Intelligence and Judiciary committees in their chamber — are expected to release a bill soon that is more deferential to the intelligence community than the House Judiciary's bill. Privacy advocates Sens. Ron Wyden (D-Ore.) and Rand Paul (R-Ky.) are also expected to weigh in on the other end of the spectrum, with a bill requiring warrants for any and all queries of the database.

Back in the House, the Freedom Caucus is also starting to discuss its approach to a Section 702 reauthorization in meetings, though the group has not yet taken a stand on how it will vote.

Its leader, Rep. Mark Meadows (R-N.C.) is already raising concerns related not just to the central debate about "where does national security and going after terrorists infringe on the rights that are constitutionally protected," as he said, but also related to the intelligence community's internal practice of "unmasking" of U.S. persons, that Meadows believes "infringed on our Fourth Amendment rights" against unlawful search and seizure.

[Nunes-led House Intelligence Committee asked for ‘unmaskings’ of Americans]

Unmasking became a buzzword earlier this year, after Nunes accused Obama administration officials of improperly revealing the identities of U.S. persons picked up in foreign surveillance reports, intimating that at least one of those persons was affiliated with President Trump. According to NSA Director Adm. Mike Rogers, only about 20 members of the agency are permitted to approve requests to "unmask" the identities of U.S. persons who are picked up in Section 702 and other surveillance of foreign agents overseas, and only certain government officials privy to those reports can make an unmasking request. If the unmasking request is deemed critical to understanding the nature of the intelligence, the identity of that U.S. person is unmasked only to the requesting party.

The House Judiciary bill also changes the procedure by which unmasking requests are made. But given those concerns, Meadows suggested he wants to see even more protections for how information on Americans' communications is accessed, endorsing the idea of "look[ing] at warrants and the admissibility of evidence" — a combination, effectively, of both the House Judiciary Committee's and Schiff's proposals.

"It's making sure we go after the bad guys but that we don't have a dragnet that pulls in U.S. citizens with constitutionally protected privilege," Meadows added.

Meadows guessed, however, that it would still be a few weeks before the Freedom Caucus officially weighs in on the Section 702 debate and the House Judiciary Committee's bill.

"When I tell you I've got the votes to stop it, I want to make sure I've got the votes to stop it," he said.

Ellen Nakashima contributed to this report.

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