President Barack Obama has appealed to US senators to prevent key national security surveillance measures from lapsing at midnight today, warning that inaction on their part could lead to a terrorist attack.
"I expect them to take action, and take action swiftly," Mr Obama said on Friday, trying to break a legislative impasse over the USA Freedom Act.
The measure was passed comfortably by the House this month but ran aground in the Senate. His comments were the strongest to date on the consequences of failure by Congress to support the legislation.
Without its endorsement today, the National Security Agency (NSA) will lose controversial powers to access data caught in a vast telephone dragnet, and investigators will be blocked from launching "roving wiretaps" targeted at terrorist suspects who use multiple disposable cellphones.
"I don't want us to be in a situation in which for a certain period of time those authorities go away, and suddenly we're dark," Mr Obama told reporters in the Oval Office. "Heaven forbid we've got a problem where we could have prevented a terrorist attack or apprehended someone who is engaged in dangerous activity, but we didn't do so simply because of inaction in the Senate."
The US Senate is scheduled to hold a special session this afternoon to consider the measure.
The battle over the USA Freedom Act reflects the perennial tug of war in the US between civil liberties and security.
On one side are those who are averse to doing anything to hold back national security agencies just when fears of a lone-wolf attack on US soil is at a high. On the other are those aghast at revelations of the NSA's sweeping dragnet by its former contractor Edward Snowden.
The battle lines this time are not drawn along party lines, said observers. Rather, it is down to a split in the Republican Party.
Explained Mr Ken Gude, senior fellow with the national security team at the Centre for American Progress: "Democrats in Congress are mostly aligned with the intelligence community and the Obama administration in supporting the USA Freedom Act.
"The battle lines among Republicans are those like Senator Rand Paul and most in the House caucus who favour a more libertarian policy on security and Republicans like Senators Mitch McConnell and Lindsey Graham who back the national security state."
The USA Freedom Act, if passed, would put an end to the domestic dragnet but leave much of the surveillance apparatus of US intelligence agencies intact.
The biggest change is to move the domestic phone data the government collects into the hands of private telcos and then putting in place some checks into how the government can query that data.
The NSA would still be able to continue collecting data about Americans if the information originates outside the US and it would also be able to continue tapping private links between data centres or attempting to break encryption. The Act would also do little to stop the US phone tapping of world leaders that caused a diplomatic uproar in 2013.
Experts like Mr Gude and Associate Professor David Schanzer from Duke University's Sanford School of Public Policy believe the measure will likely pass despite a bruising fight.
This article was first published on May 31, 2015.
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