The House of Representatives unanimously approved a bill Saturday that would assure retroactive pay to more than 800,000 federal workers furloughed during the current US government shutdown.

Bitterly-divided lawmakers used a rare weekend legislative session to unite on the issue, the first significant coming together amid a federal work stop that has entered its fifth day, with no end in sight.

The bill would provide backpay to federal employees regardless of the length of shutdown, essentially ensuring a paid leave for the vast number of employees currently forced off the job.

The White House has endorsed the measure. It now goes to the Senate, which also came into session Saturday but it remained unclear whether the chamber would take up the pay bill before Monday.

"The House just took another step to try and ease the pain of the federal government shutdown, assuring federal employees will get their back pay," number two House Republican Eric Cantor told reporters after the vote.

The House also approved a measure allowing chaplains to conduct religious services on federal property including military bases during the shutdown.

The Republican-controlled House has now voted on a dozen mini-bills to fund government by piecemeal, a tactic strongly opposed by Democrats.

Republican leadership, bowing to the party's hard-conservative bloc, has stood fast on insisting that any stopgap spending measure be contingent on rolling back all or part of President Barack Obama's health care law.

Obama and Democrats are vehemently opposed, and the shutdown has now careened dangerously close to the next fiscal hurdle: the need to raise the US borrowing limit by October 17 or face a potentially catastrophic debt default.

Cantor pinned the blame squarely on Obama.

"This shutdown has been brought about by the president's unwillingness to sit down and talk with members of Congress," the House Republican leader said.

With the shutdown likely to carry into a second week, aides and lawmakers conceded that there are no substantive talks between the two feuding sides.

With Obama cancelling his upcoming Asia trip, Republicans see a chance to pry open the doors of negotiation.

"That's a unique opportunity then. If he's here this weekend, we are here this weekend," said Republican Kevin McCarthy.

"This can all end. All the president has to do is sit down along with the Senate Democrats and we can move forward."