WASHINGTON — Intelligence and law enforcement officials scrambled Thursday to prepare for the possible shutdown of several programs used to track terrorism suspects in the United States as brinkmanship in the Senate threatened to end the government’s bulk collection of domestic telephone data.
Officials stressed that the fate of the controversial National Security Agency’s once-secret program is entwined with a handful of lesser-known authorities in the Patriot Act, which was passed after the Sept. 11, 2001, terrorist attacks.
Three key provisions in the law are set to expire Monday unless Congress acts to amend or extend them. The House has passed a reform bill, but it has bogged down in the Senate, which is racing to finish work so members can leave on a holiday recess that runs through next week.
In addition to the NSA bulk collection of phone data, programs set to expire include one that allows the FBI to collect business records like credit card and banking data for use in terrorism investigations.
Another authorizes so-called “roving wiretaps,” which permit the FBI to eavesdrop on every phone used by a suspected terrorist without seeking separate court warrants for each one.
A third program helps the FBI track a so-called “lone wolf,” an individual suspected of planning a terrorist attack, even if he or she has no known link to a terrorist group.
Senators spent Thursday afternoon trying to clear a political logjam over whether and how to renew those provisions. They have three options.
Lawmakers could do nothing and leave Washington on schedule Friday for a weeklong holiday. If they do, programs that the FBI and intelligence officials consider vital for national security would be forced to shut down, at least until Congress returns in June and reconsiders the issue.
As an alternative, they could vote for a compromise House bill that passed last week. It would shift domestic phone records from NSA control back to the phone companies, and require a court order to access them.
On Thursday, supporters of that option appeared unlikely to round up the 60 votes they need to proceed.
The other option is a temporary extension of the current provisions. The Senate probably would add language to put the program on stronger legal ground, since a federal appeals court ruled recently that the NSA was overstepping the law by collecting data from every U.S. phone call.
The short-term fix appeared most likely.
“There will be an extension,” said Sen. John Cornyn of Texas, the No. 2 Republican on the Senate Intelligence Committee. “I just can’t tell you how long. … Just making sure we don’t go dark is the issue.”
Investigators use the NSA database of phone records to search for links between phone numbers used by known or suspected terrorists and individuals in the U.S. The records contain the date, time, duration and numbers dialed, but not the content.
NSA officials will begin Friday to shut down the program if Congress doesn’t act, the Justice Department advised lawmakers.
The NSA needs to begin winding the program down before the law expires “to ensure that it does not engage in any unauthorized collection” of U.S. phone records, according to a legal memo sent to lawmakers Wednesday.
If the authority expires, the NSA is unlikely to expunge records already in its databases, according to a U.S. official. A shutdown would force the NSA to stop collecting and storing new data, however.
If the authority is extended after a few days or weeks, the NSA could fill any gaps by collecting historical data that the phone companies are required to keep, said the U.S. official, who spoke on condition of anonymity to discuss intelligence matters.
In the meantime, investigators sought to ensure that the deadline would not upend ongoing investigations.
In a speech Wednesday, FBI Director James Comey said losing the ability to use “roving wiretaps” or track so-called “lone wolves” in terrorism investigations would be a “big problem.”
The bureau has been able to follow criminal suspects as they changed phones since the 1980s, Comey said, and the Patriot Act extended that capability to terrorism cases.
“That’s going to go away” unless the law is reauthorized, Comey said.
Hanging over the Senate debate is the threat by Sen. Rand Paul, R-Kentucky, and several allies to block any renewal of the program, which they consider a violation of civil liberties.
Paul, who is seeking the 2016 Republican presidential nomination, held the Senate floor for 10 hours Wednesday to argue for ending the NSA program outright.
It was uncertain if his maneuver led to a meaningful delay of Senate business, the traditional definition of a filibuster, or if it would have any other effect.


