This second referendum, if it were to take place, would be on the Brexit deal May has struck with the European Union.
Prime Minister Theresa May on Monday warned MPs against supporting a second Brexit referendum, as calls mounted for a public vote to break the political impasse over the deal she has struck with the EU.
"Let us not break faith with the British people by trying to stage another referendum," she told parliament.
"Another vote... would do irreparable damage to the integrity of our politics," May said, adding that a second vote "would likely leave us no further forward".
Britain voted to leave the European Union in a shock referendum in 2016 and is set to do so on March 29 next year, although the prime minister is struggling to persuade parliament to accept a divorce deal she struck last month.
'We must honour our duty'
The government postponed a scheduled parliamentary vote on the agreement last week and on Monday May said it would finally be held in the week starting on January 14.
"We must honour our duty to finish this job," she said.
May has said she is engaged in talks with the EU to seek "assurances" about the Brexit deal, but European Commission spokesman Margaritis Schinas on Monday said "no further meetings with the United Kingdom are foreseen".
The draft deal was agreed only after tortuous talks in Brussels that began in March last year and EU leaders have ruled out any renegotiation, while the British economy has been languishing due to uncertainty over Brexit.
Blair vs May
May last week survived a confidence vote initiated by members of her own Conservative Party because of her Brexit strategy, but she is badly weakened after a third of her parliamentary party voted to be rid of her.
Jeremy Corbyn, leader of the main opposition Labour Party, on Monday said Britain was in "a constitutional crisis and the prime minister is the architect of it".
"The prime minister has cynically run down the clock, trying to manoeuvre parliament into a choice between two unacceptable outcomes" -- her deal or no deal, Corbyn said.
In the face of calls for a second referendum to resolve the impasse, May has argued that this would betray the 2016 result and undermine public confidence in politics.
The issue provoked an extraordinary public clash on Sunday between May and former prime minister Tony Blair, a leading supporter of continued EU membership and of holding another poll.
May accused Blair of insulting voters and trying to undermine her government by meeting officials in Brussels.
Blair, who was premier between 1997 and 2007, in turn accused the Conservative leader of being "irresponsible".
But campaigners for a referendum said May's comments on Monday showed that the idea was being taken seriously.
"A new public vote would be different from the referendum in 2016 because we now know more about what Brexit means," said Margaret Beckett, an MP from the main opposition Labour Party and "People's Vote" supporter.
"Any effort to force Brexit over the line without checking that it has the continued consent of the British people will only reinforce divisions," she said.
MPs to vote on options?
May has delayed a crucial vote by MPs on the draft Brexit deal until next month, leaving the political scene in limbo.
If parliament fails to approve the text, Britain could crash out of the EU regardless -- a prospect that experts warn could lead to serious trade disruption and trigger a financial crisis.
Dozens of MPs from all sides support a second referendum and there have been reports that officials are considering the possibility of giving the public a vote.
Another proposal being put forward if May's deal does not pass parliament is for MPs to hold indicative votes on different options to work out what steps to take next.
Business Secretary Greg Clark told BBC radio that "parliament should be invited to say what it would agree with" instead of just criticising May's deal.
Other cabinet ministers are also reported to favour a scenario of asking MPs to vote on options that could include a no-deal Brexit, a second referendum, and a "Norway option" to keep closer economic ties with the EU.
Asked about the possibility of holding a series of votes like this, May's spokesman on Monday said there were