(CNN) Senators are expected to leave Washington on Thursday without striking an agreement on a crucial surveillance law, setting the stage for various national security provisions to expire on Sunday.
The Senate debate collapsed over whether to give some concessions to the law's critics, such as votes on their amendments to the bill overhauling the surveillance law, or to pass a temporary extension providing more time to negotiate.
The Senate leadership hoped to vote on the bill as soon as Thursday and pledged that if the authorities lapsed it would only be for a short period. But its critics, including Sens. Rand Paul of Kentucky and Mike Lee of Utah, argued that the changes didn't go far enough to fix the surveillance law known as the Foreign Intelligence Surveillance Act, or FISA.
"Senate Republican leaders are trying to ram through fake FISA amendments without any real changes," Paul tweeted. "I will object. I continue to stand with @realDonaldTrump in his reservations to this bill."
Lee asked for unanimous consent for a 45-day FISA extension. Sen. Richard Burr, the chairman of the Intelligence committee, objected.
"I'll let us go dark," the North Carolina Republican said, noting that the Senate will come back next week and can soon pass the House bill.
Senate Majority Leader Mitch McConnell said on Thursday that it was a question not if the bill passed the Senate but when.
"I hope none of our colleagues choose to force these important national security tools to temporarily lapse for the sake of making a political point which will not change the result," said McConnell.
The measure that passed the House this week extends three provisions that would otherwise expire: access to certain "business records" for investigations, "roving wiretaps" allowing the government to eavesdrop on multiple devices, and allowing investigations of a foreigner -- or a "lone wolf" -- suspected of terrorism not connected to a terrorism organization.
The bill also includes additional privacy protections, including a ban on using geolocation or cell site location data, under the law's provisions dealing with business records.
It includes additional checks on the FBI's use of surveillance warrants obtained through the FISA court. The changes were a result of misconduct documented by the Justice Department inspector general in the FBI's warrants for former Trump campaign adviser Carter Page during its investigation of Russian interference in the 2016 presidential election.
President Donald Trump tweeted that "many" Republican senators want him to veto the bill.
He said, "Many Republican Senators want me to Veto the FISA Bill until we find out what led to, and happened with, the illegal attempted 'coup' of the duly elected President of the United States, and others!"
Sen. John Cornyn, Republican of Texas, said there is "a lot of noise" regarding the bill but said he hopes Trump "follows the advice" of Attorney General William Barr and signs it.
On Wednesday, Barr said the bill "contains an array of new requirements and compliance provisions that will protect against abuse and misuse in the future while ensuring that this critical tool is available when appropriate to protect the safety of the American people."