The pound dropped to its weakest level in nearly 18 months and government bonds rallied as U.K. Prime Minister Theresa May was said to have called off a crucial vote in Parliament on her Brexit deal.
The ruling is in line with an opinion delivered last week by a Court legal adviser.
The delay in signing off the deal, just months before Britain is set to end its four-decade membership of the bloc on March 29, sent the pound plunging to an 18-month low.
"The deal would be rejected by a significant margin. we will therefore defer the vote scheduled tomorrow", the United Kingdom leader told the House of Commons.
The latest development came hours after May's spokeswoman said the vote was going ahead as planned on Tuesday. "So the government will step up its work in preparation for that potential outcome", she told parliament.
Postponing the vote would be a new blow for May, who became prime minister after Britain's 2016 decision to leave the EU.
"For as long as we fail to agree a deal, the risk of an accidental no deal increases", she told MPs.
Eurosceptics in May's Conservative party and the Northern Irish party that props up her government hate the provision in the Brexit deal created to keep open the border with Ireland - the so-called backstop. "This is the best deal and approving this deal would be a good thing, but for sure it's up to them".More news: Michelle Obama's Becoming Tour Coming to Phoenix
More news: Oil prices under pressure amid global market unease
More news: Google For You Tab Expands To iOS Devices & 130 Countries
Following a weekend of pressure on Mrs May about the details of the deal, Downing Street could make some concessions on certain parts of the blueprint for Britain's exit.
"There is still a majority to be won in parliament with additional reassurance on backstop", she said, adding that she would also be "looking closely at new ways of empowering the House of Commons to ensure that any provision for a backstop has democratic legitimacy".
The prime minister pushed back in an interview with the Mail on Sunday, saying her party members risk helping the opposition Labour Party's push for power if they defeat her accord.
Reacting to the reports of a possible delay, Scottish First Minister Nicola Sturgeon said it demonstrated "pathetic cowardice by a PM and government that have run out of road".
Angry Tory rebels and Labour MPs said they would try to force the government to hold a vote, even though a government source said there would be no vote on a business motion to cancel Tuesday's vote.
Should the Prime Minister not secure a victory in the vote, then interest will turn to the numbers.
But analysts said sterling's weakness on Monday reflected deepening uncertainty as well as concerns about May's future as prime minister.
In response, EU President Donald Tusk called a special summit of the other 27 leaders to discuss Brexit on Thursday, December 13, at the start of a two-day Brussels meeting that May is due to attend.