UPDATE 10:10 p.m. EDT: President Obama issued a statement, praising the Senate for taking "an important -- if late -- step forward tonight. We call on the Senate to ensure this irresponsible lapse in authorities is as short-lived as possible. On a matter as critical as our national security, individual senators must put aside their partisan motivations and act swiftly."

The American Civil Liberties Union called for changes to the USA Freedom Act before it is adopted. "Congress should take advantage of this sunset to pass far reaching surveillance reform, instead of the weak bill currently under consideration," Michael Macleod-Ball, acting director of the ACLU legislative office in Washington, said in a statement.

UPDATE 9:45 p.m. EDT: The Senate adjourned until noon EDT Monday, allowing Section 215 of the Patriot Act to expire at midnight EDT. The Senate is expected to consider amendments to the USA Freedom Act. If approved, the measure will have to go back to the House for reconsideration.

UPDATE 8:35 p.m. EDT: With no further votes scheduled for Sunday night, provisions of the U.S. Patriot Act were poised to expire at midnight. The Senate met in a rare Sunday session, agreeing only to debate the USA Freedom Act but taking no steps to prevent the at least temporary shutdown of government anti-terror surveillance programs.

Original post:

The U.S. Senate Sunday took up the USA Freedom Act aimed at reforming the government's aggressive data-collection programs adopted in the wake of the Sept. 11, 2001, terror attacks. The Senate, in a rare Sunday session, took up the measure just hours before provisions of the U.S. Patriot Act were set to expire.

The Senate voted 77-17 to invoke cloture, allowing the measure to proceed.

"The nature of the threat we face is very serious. It is very aggressive. It is sophisticated. It is geographically dispersed. And it's not going away," Senate Majority Leader Mitch McConnell said in urging action.

"This is a debate over the Bill of Rights. This is a debate over the Fourth Amendment. This is a debate over the right to be left alone," Sen. Rand Paul, R-Ky., said in opposing any legislation that would preserve the National Security Agency's ability to collect massive amounts of telephone data -- whether held by the federal government or by the phone companies, as provided for under the new legislation.

Paul accused supporters of the surveillance programs of using fear "to take a little of your liberty by making you afraid." He called for amending the bill to require an individual's name to be on a warrant before data can be collected and to bring the law up to constitutional standards. He also urged that any information collected "under less than constitutional standards" be used only against foreigners.

Earlier in the day CIA Director John Brennan voiced concern expiration of the government surveillance programs would lead to a terrorist attack. In an appearance on CBS's "Face the Nation," Brennan accused senators of grandstanding.

“The tools that the government has used over the last dozen years to keep this country safe are integral to making sure that we’re able to stop terrorists in their tracks,” Brennan said.

Allowing the programs to lapse "is something that we can't afford to do right now, because if you look at the horrific terrorist attacks and violence that is being perpetrated around the globe, we need to keep our country safe. And our oceans are not keeping us safe the way they did a century ago," Brennan said.

The House overwhelmingly passed the USA Freedom Act, 338-88, but McConnell said it lacks the safeguards necessary to guarantee phone companies will store the data so that it would be available to government analysts once a warrant is obtained.

Sen. Dan Coats, R-Ind., called for more debate on the issue saying the Senate "is not a rubber stamp for the House."

The Patriot Act was passed in the wake of the Sept. 11, 2001, terror attacks, and some of its provisions are considered draconian by civil libertarians. NSA data collection practices under the act were revealed by former NSA contractor Edward Snowden, who has sought asylum in Russia to avoid U.S. prosecution for releasing classified information. Snowden's revelations set off a firestorm.

"Even the authors of the Patriot Act say the Patriot Act doesn't give the authority to collect all that information all the time," Paul said.

Sen. Patrick Leahy, D-Vt., urged colleagues to adopt the House bill. "It is a reasonable, responsible way forward," he said. "Don't duck behind not doing anything. … Not a single American would think that's a responsible solution."