Britain's parliament was due to vote on Thursday on seeking a last-minute Brexit delay and Prime Minister Theresa May sought to use the prospect of a long extension to push lawmakers to back her EU divorce deal, which they have twice rejected.
Little more than two weeks before Britain is due to leave the European Union, with no firm agreement in place to smooth the transition, May tried to up the pressure on eurosceptic rebels in her Conservative Party.
With her authority at an all-time low, May's finance minister Philip Hammond said the prime minister's plan was back on the agenda.
That plan, struck by May after two-and-a-half years of tortuous negotiations with the EU, was defeated heavily in parliament on Tuesday for the second time, after a resounding rejection in January.
"Quite a number of colleagues changed their mind on this issue between the January vote and the vote earlier this week," Hammond told Sky News.
"It's clear that the House of Commons has to find a consensus around something and if it isn't the prime minister's deal I think it is likely to be something which is much less to the taste of those on the hard Brexit wing of my party."
Donald Tusk, head of the European Council which groups the national leaders of the bloc, said he favoured a long extension if London asked for one. An official said that meant a delay of at least a year.
The other 27 EU member states must agree to any extension.
But there was no sign of a major shift in the views of pro-Brexit lawmakers who have so far thwarted May.
Andrew Bridgen, a eurosceptic lawmaker from May's Conservative Party accused her of pursuing a "scorched earth" policy of destroying all other Brexit options to leave lawmakers with a choice between her deal and a delay of a year or more.
BREXIT DAY
May is also hoping to win over the Northern Irish Democratic Unionist Party (DUP) that props up her minority government in parliament and which has so far refused to back her plan.
DUP leader Arlene Foster said the party was working with the government to try to find a way of leaving the EU with a deal.
On Wednesday, Britain's parliament rejected the prospect of leaving the EU without a deal, paving the way for Thursday's vote that could delay Brexit until at least the end of June.
While the motion approved by parliament has no legal force - March 29 remains the day enshrined in law that Britain will leave the EU - and ultimately may not prevent a no-deal exit, it carries considerable political force.
Sterling surged, hitting nine-month highs against the U.S. dollar and a nearly two-year high against the euro, as investors saw less chance of Britain leaving the EU without a transition deal to smooth its exit.
Although May supported the idea of ruling out a no-deal Brexit in the short term, she suffered another humiliation when four of her ministers disobeyed her and abstained from a vote on an amendment which ruled out a no-deal Brexit in any circumstances and was passed by parliament.
May could make a third attempt next week to get parliamentary approval for her deal.
An influential member of the European Parliament said Britain was likely to get the bloc's approval for a Brexit delay if it asks for one.
But the EU would not change the divorce deal it has agreed with London during any extension or negotiate future ties, said Danuta Hubner, who sits on a six-strong panel dealing with Brexit in the European Parliament.
A senior official in Britain's opposition Labour Party said it would support a limited Brexit delay in order to seek a compromise that can be backed by lawmakers.
"We will be putting an amendment down to ensure parliament considers an extension, it doesn't necessarily have to be a long extension," Labour's finance spokesman John McDonnell told Sky News.
Lawmakers filed amendments to the government's motion on delaying Brexit that is due to be put to a vote later on Thursday.
One amendment seeks to rule out a second referendum while another is for a second referendum. A Labour Party amendment calls for a delay to Brexit to allow parliament time to find an alternative way forward.
Britons voted by 52-48 percent in a 2016 referendum to leave the EU, a decision that has divided the main political parties and exposed deep rifts in British society, bringing concerns about immigration and globalisation to the fore.
The default position if nothing else is agreed remains that Britain will exit with no deal on March 29, a scenario that business leaders warn would bring chaos to markets and supply chains. Brexit supporters say in the longer term it would allow Britain to thrive and forge trade deals across the world.