Washington: The US Senate voted on Thursday to extend until 2015 controversial counter-terrorism search and surveillance powers at the heart of the Patriot Act adopted after the September 11, 2001 attacks.
Lawmakers adopted the measure 72-23 just hours before it expires at midnight (0400 GMT Friday), sending the bill to the House of Representatives. Voting in the House was not expected until 8:00 pm (0000 GMT), according to a congressional aide.
With the clock ticking, President Barack Obama -- currently on a European tour -- would also have to sign the act for it to pass into law.
FBI and intelligence officials have warned that if the Patriot Act is not extended by the deadline they would be robbed of crucial tools in the fight against terrorism -- including wiretapping.
"I have no doubt that the four-year Patriot Act extension, that members of both parties will agree to today, will safeguard us from future attacks," said Senate Republican leader Mitch McConnell.
Congress has debated whether to extend the act just temporarily, longer-term or permanently in recent months. In February, Congress approved a three-month extension to allow time for negotiations.
In play are provisions allowing authorities to use roving wiretaps to track an individual on several telephones; track a non-US national suspected of being a "lone-wolf" terrorist not tied to an extremist group; and to seize personal or business records or "any tangible thing" seen as critical to an investigation.
While the White House backs extending those powers, the law has drawn fire from an unusual coalition of liberal Democrats and Republicans tied to the arch-conservative "Tea Party" movement who say it goes too far.
Republican conservative Rand Paul sought to impede the extension by adding on several amendments, including a ban on inspecting some archives of arms sellers during terror investigations. That measure was rejected in an 85-10 vote.
Democratic Senator Patrick Leahy called for greater congressional surveillance in counterterrorism inquiries.
FBI director Robert Mueller wrote to Congress leaders on Wednesday to warn them of the urgency of the matter.
"It is important that these tools be reauthorized without lapsing," Mueller wrote, opposing proposed amendments which he said "would adversely impact our operations."
"Certain amendments currently being proposed would impose unique limitations on our ability to investigate foreign spies and terrorists and protect Americans against foreign threats."