WASHINGTON (AFP) - United States Senate Republicans on Tuesday blocked a sweeping overhaul of a National Security Agency (NSA) programme that would have ended the government's controversial bulk collection of data about Americans.
The vote marks a blow for US President Barack Obama, who had supported the reforms, and sets up a showdown in coming months as key surveillance provisions expire in mid-2015.
The USA Freedom Act, also backed by Silicon Valley groups and major technology firms, marked an ambitious bipartisan effort to reform the nation's surveillance apparatus following the revelations of government spying by former security contractor Edward Snowden.
The measure earned a majority vote, 58-42, with four Republicans joining all but one Democrat in favor. But it fell short of the 60-vote threshold to overcome blocking tactics.
It would have reined in the NSA, whose clandestine programme has been scooping up vast amounts of electronic data on innocent US citizens as it pursues information on terror threats.
It would have replaced the NSA's blanket authority with a far narrower one allowing it to obtain call records from phone companies but only in specific cases.
"Obviously I'm disappointed by tonight's vote," said the Bill's sponsor, Senator Patrick Leahy.
"This lifelong Vermonter will not give up the fight."
Proponents had been eager to progress before January, when they envision a more difficult path for the Bill in a new Congress controlled by Mr Obama's Republican foes, after the GOP swept to victory this month in midterm elections.
The Bill would have crucially modified the Patriot Act, hastily approved in the aftermath of the September 2001 attacks on the United States, by changing the secret Foreign Intelligence Surveillance Court to include a panel of advocates who would argue for civil liberties.
The reforms are likely to face another test next year, as the Patriot Act's Section 215, which contains the legal justification for the dragnet phone metadata programme, comes up for renewal in June.