Congress to vote on NSA spying powers

The U.S. House of Representatives has forced a vote that could cut funding for the National Security Agency (NSA) and limit the scope of its vast surveillance activities, marking the first potential constraints on the agency's powers since former security contractor Edward Snowden leaked documents detailing the its extensive secret surveillance program.

The vote could take place as early as Wednesday.

Rep. Justin Amash (R-Mich.) postponed an amendment to a wider defense bill, which "ends authority for the blanket collection of records under the Patriot Act,” and limits surveillance to individuals under investigation.

House opponents to the surveillance program, kinown as PRISM, have tabled a second amendment to cut back the NSA's funding.

President Barack Obama, who has spoken out in defense of the program and said the widespread spying has prevented more than 50 terrorist plots, sent the NSA chief, Gen. Keith Alexander, to Capitol Hill to urge both Republican and Democratic politicians to oppose the move to restrict the agency's activities.

"We oppose the current effort in the House to hastily dismantle one of our intelligence community's counterterrorism tools," White House spokesman Jay Carney said in a late-night statement. "This blunt approach is not the product of an informed, open or deliberative process."

Amash tweeted on Tuesday: "Do Members of Congress want to go on record supporting unconstitutional, blanket collection of all Americans' phone records? We'll find out."

Later, he tweeted: "US gov't has come out in full force against you, the American people. I will always stand with you & the Constitution I swore to defend."

Carney said Obama was still open to discussing the balance between security and privacy with Congress and the American public, but that he wants an approach that properly weighs what intelligence tools are needed to keep Americans safe.

The amendments, however, face stiff challenges. The House version would still have to be reconciled with a version being drawn up in the Senate, and any eventual bill could still be vetoed by Obama.

Leaders of the Senate Intelligence Committee have opposed them, citing the NSA's thwarting of attacks.

“The FISA business records program has contributed to disrupting numerous terrorist attacks against our nation,” said Senate Intelligence Committee Chairman Dianne Feinstein (D-Calif.) and Vice Chairman Saxby Chambliss (R-Ga.), in a statement Tuesday. "Any amendments to defund the program on appropriations bills would be unwise."

The PRISM revelations caused an international uproar against what many view as an invasion of privacy.

Numerous countries, including Germany and Brazil, have also spoken out against the program.

Tea Party conservatives, liberal Democrats and libertarians like Amash have all backed the proposed amendments.