The U.S. Senate is set for a new showdown on restarting the government's massive national security surveillance program.
Senate Majority Leader Mitch McConnell has scheduled votes Tuesday on amendments to the USA Freedom Act, a measure the House of Representatives has already approved.
Kevin McCarthy of California, the House majority leader, said amendments contemplated by the Senate "would bring real challenges" in getting the House to go along.
"The best way to make sure America is protected is for the Senate to pass the USA Freedom Act," McCarthy said, referring to the House version.
The White House also urged the Senate Tuesday to pass the House version of the bill, which President Barack Obama supports.
The amendments that Senators will vote on later Tuesday include extending from six months, as passed by the House, to one year the transition period for switching data storage from the NSA to the telecommunications companies. The government would still be able to search the records on a court-ordered, case-by-case basis to fight terrorism.
McConnell said the longer time frame is necessary, but Mike Rogers, the NSA director, has said six months is sufficient.
The Senate majority leader has also vowed to hold two other votes Tuesday: one amendment would require the director of national intelligence to certify that the NSA can effectively search records held by the phone companies in terrorism investigations, the second would require the phone companies to notify the government of policy changes on how long they hold records.
Any Senate-approved changes to the reform proposal would also then have to be accepted by the House, further delaying the restart of the data collection that the Senate allowed to lapse at midnight Sunday. The lapse has forced the NSA to shut down, at least temporarily, two other programs, including a "lone wolf" tracking provision that has never been used and a roaming wiretap program.
During a closed-door House GOP meeting Tuesday morning, several members expressed deep concerns about the planned Senate amendments.
There is wide congressional support for continuing the data collection in some form.
"Nobody wants to see privacy rights of American citizens undermined," said Senator John Cornyn, a Texas Republican. "But we all are adult enough to know that there has to be a balance" between protecting privacy rights and collecting information to keep the country secure against terrorist attacks.
However, Cornyn also urged senators not to turn their backs on what he characterized as an effort to improve the bill.
"Since when did the U.S. Senate outsource its decision-making to the other body across the Capitol? We have a bicameral Legislature, a Senate and a House, for a reason. … The Senate should not be a rubber stamp for the House, or vice-versa," he said.
Cornyn supported extending the time for transferring the data collection duties from the NSA to phone companies from six months, as the House approved, to a year.
However, Senator Patrick Leahy, a Democrat, said Tuesday, "If we start amending it, we do not know how much longer it is going to take, and we may end up with no protections.
“The USA Freedom Act passed overwhelmingly in the House of Representatives, has strong bipartisan support here, is supported by the head of intelligence for the United States, is supported by our attorney general. It is a step forward, because ultimately we protect the privacy of individuals," Leahy said.
House: No changes
But two high-ranking members of the House Judiciary Committee, Republican chairman Bob Goodlatte and ranking Democrat John Conyers, warned the House would not accept further changes to its proposal.
If the bill fails amid congressional politics, the collection of data cannot resume.
Congress passed the U.S. Patriot Act, which allowed the government's domestic surveillance program, after the September 11, 2001, terrorist attacks.
Several Senate votes on the reforms have been blocked by Kentucky Republican Rand Paul, who is seeking the 2016 Republican presidential nomination. Paul has denounced the NSA program as a violation of Americans' privacy, and said the House bill does not go far enough in reforming it.
But Republican Senator John McCain, who lost the 2008 presidential election to Obama, said Paul "obviously has a higher priority for his fundraising and political ambitions than for the security of the nation."
The telephone data collection from millions of calls was first revealed two years ago by former NSA contractor Edward Snowden, now living in asylum in Russia. It included phone numbers, the dates and duration of calls, but not the content.
Some material for this report came from AP.