Republicans in the US House of Representatives have delayed a vote on a short-term bill to raise the nation's debt limit by $900 billion, Democratic sources said.
An aide to House Democratic leader Nancy Pelosi said Steny Hoyer, the Democrat's top vote counter in the House, had told his party members that Republicans had decided to postpone the vote.
Republicans had been trying to rally up enough support to pass the bill, but the vote was expected to be close.
A Republican aide said the House would vote on the bill later on Thursday evening.
The vote was originally scheduled to be around 10pm GMT.
Approval of a plan by House of Representatives Speaker John Boehner would break the deadlock in Washington over a US debt crisis that has concerned markets.
The crisis has raised the prospect that the government of the world's largest economy will run out of money to pay its bills in less than a week.
US President Barack Obama has threatened to veto the bill and a majority of the Democratic-controlled Senate has vowed to vote against it.
But a successful vote in the House would give the bill legitimacy and make it a crucial element of the legislative chess game that is likely to play out until the 2 August deadline.
A defeat of the bill could deepen the crisis, swinging the momentum toward a rival Democratic plan in the Senate, but leaving no clear way to overcome entrenched opposition from fiscally conservative Tea Party Republicans in the House.
The Treasury says it will run out of spending money next Tuesday unless Congress agrees to raise the $14.3 trillion debt ceiling.
Even if an 11th-hour compromise emerges, the US could lose its top-notch credit status if ratings agencies are not convinced it has done enough to address its bulging debt burden.
The White House has warned of 'catastrophic' consequences if a deal is not reached, rejecting the idea that Mr Obama could invoke an obscure constitutional clause to raise the debt limit.
After weeks of bickering and setbacks, some common ground has emerged between rival Republican and Democrat plans to cut the deficit and raise the debt limit.
A bill being pushed by top Senate Democrat Harry Reid and backed by the White House would cut $2.2 trillion from the deficit over ten years without raising taxes.
Mr Reid has said Mr Boehner's plan would be 'dead on arrival' but that he could incorporate elements of it in a way that could win support from both parties.
Mr Boehner's two-step plan contains a crucial sticking point - it would only extend the Treasury's borrowing authority by a few months, something Mr Obama has said is unacceptable.
