It appears likely that key US counterterrorism laws that allow the bulk collection of Americans' phone records will expire. The US Senate's extraordinary weekend sitting has failed to extend the contested program.
The US Senate held a rare Sunday session to prevent key post-September 11 anti-terrorist provisions from expiring, but it appears lawmakers have failed to produce an 11th hour deal.
The main issue is a program by the National Security Agency (NSA) that allows it to collect Americans' phone records in bulk. Failure to agree means that some of the NSA's snooping methods would be illegal as of midnight (0400 UTC), when key provisions in the USA Patriot Act expire.
Opposition to their extension has primarily come from Kentucky Senator Rand Paul, who is seeking the Republican nomination for the 2016 presidential election. He has made good on earlier promises and blocked the chamber from advancing a solution.
"The Patriot Act will expire tonight," said Paul on Sunday. There has been no clear majority - 60 of 100 votes - for either an extension to the present rules or the new bill, the USA Freedom Act, that has already passed the House of Representatives.
The proposed Freedom Act would replace three key surveillance provisions of the Patriot Act. That includes scaling back the NSA's powers, and forcing it to stop the telephone data program - which collects the records of millions of Americans, most of whom have no connection to terrorist activities.
The Freedom Act would extend the existing surveillance program for six months while the new system gets up and running.
Lapse likely to be temporary
Sunday's meeting was called by Senate Majority Leader Mitch McConnell. During that session, the Senate voted 77-17 to move ahead on the Freedom Act, but McConnell came up short of reaching a solution.
Paul served notice that he would assert his prerogative, under Senate rules, to delay a vote for several days.
But the lapse is likely to be only temporary. Senate rules mean it will probably be the middle of the week before the chamber can vote on whether or not to pass the Freedom Act.
Paul did acknowledge after the procedural vote: "This bill will ultimately pass."
The NSA program had been secret until it was revealed by former NSA contractor Edward Snowden almost two years ago. The revelations caused an uproar in Germany, particularly the news that the NSA had tapped the mobile phone of German Chancellor Angela Merkel.
It was revealed recently that Germany's federal intelligence service, the BND, had helped the NSA spy on European officials, agencies and individuals. Merkel's coalition partners, the Social Democrats, have called on the chancellery to release information on filters, or selectors, such as metadata and search terms used by the agencies in their espionage.
jr/cmk (AFP, AP, Reuters)