WASHINGTON — Senate Republicans have launched the opening salvo in a battle over government surveillance powers, introducing a bill to preserve intact the National Security Agency’s authority to store and search domestic telephone records.

Former NSA contractor Edward Snowden sparked a public furor in 2013 when he leaked documents showing that the spy agency was secretly collecting telephone metadata – records showing the time, date, duration and numbers called – for use in terrorism investigations.

Despite vows by President Obama to limit the program, and concern by civil liberties groups and some on Capitol Hill that it went too far in invading Americans’ privacy in the name of national security, the NSA archiving of U.S. phone records has continued unchanged.

A report released Wednesday by the Director of National Intelligence indicates that the records were checked for 227 “known or presumed” Americans last year. That compares with 248 in 2013, the first year such figures were released.

Legal authority for the program, contained in Section 215 of the Patriot Act, is set to expire June 1. That has set off a race between lawmakers who want to preserve the government’s surveillance powers and those who want to rein them in.

In an unusual procedural move, the GOP measure to extend the NSA’s so-called “bulk collection” of phone records was not considered by any Senate committee. Instead, Majority Leader Mitch McConnell, R-Ky., backed by the Intelligence Committee chairman, Sen. Richard Burr, R-N.C., moved at about 10 p.m. Tuesday to begin the process of asking the full Senate to reauthorize Section 215 without changes. A vote has not been scheduled.

Sen. Patrick Leahy, D-Vt., criticized the late-night maneuver, saying the GOP leadership in the Senate is “trying to quietly pass a straight reauthorization of the bulk collection program that has been proven ineffective and unnecessary.”

Leahy, the top Democrat on the Senate Judiciary Committee, which would have considered the legislation, said he would oppose any bill that does not contain “meaningful” reforms to the collection program.

Sen. Lindsey Graham, R-S.C., said he would consider “some reforms” to the program, “but my No. 1 goal of the Patriot Act is to make sure we don’t have another 9/11. … I will not vote for a Patriot Act that is compromised.”

A bill to limit the NSA’s bulk-collection of telephone data passed the House last year but failed in the Senate.

Intelligence officials have said the then-secret archives had helped authorities stop at least a dozen terrorist plots. Critics say only one case was discovered as a direct result of a phone record search.