Prime Minister Theresa May will state her opposition to a second Brexit referendum on Monday, telling parliament such a vote would "break faith" with British people and do "irreparable damage" to politics.
With May facing deadlock in parliament over her deal to leave the European Union and the bloc offering little in the way of concessions to win lawmakers over, more politicians are calling for a second referendum to break the impasse.
But May and her ministers have ruled out a new ballot, saying it would deepen already ugly divisions over Britain's biggest decision since World War Two and betray voters who narrowly backed leaving the EU at a 2016 referendum.
That increases the risk of Britain leaving without a deal in less than four months, a scenario some businesses fear would be catastrophic for the world's fifth largest economy.
"Let us not break faith with the British people by trying to stage another referendum," May will tell lawmakers, according to extracts of her speech released in advance.
"Another vote which would do irreparable damage to the integrity of our politics, because it would say to millions who trusted in democracy, that our democracy does not deliver. Another vote which would likely leave us no further forward than the last," she will say.
May returns to parliament after a visit to Brussels last week where she called on EU leaders to offer assurances over the so-called Northern Irish "backstop" - an insurance policy to prevent the return of a hard border between the British province and Ireland that its critics fear will trap Britain.
But while EU leaders said they were willing to help May, they warned the British prime minister she could not renegotiate the deal, agreed earlier this year.