Jeremy Corbyn has told Labour MPs the party will move to back another
vote if their own proposed Brexit deal is rejected on Wednesday.
Labour's Emily Thornberry said if the parliamentary process ended with a choice of no deal or the PM's deal, the public should decide.
Theresa May is under growing pressure to delay the 29 March Brexit date.
Labour have not yet made clear what their proposed referendum would be on, but a party briefing paper to MPs says that any referendum would need to have "a credible Leave option and Remain".
The prime minister, who will update MPs on the negotiations on Tuesday, has insisted the UK can still leave next month as planned.
The UK voted to leave the EU in a referendum in June 2016, but the withdrawal deal Mrs May negotiated with the EU has to be agreed by MPs - and it suffered a huge defeat by them last month.
Mrs May has ruled out a "meaningful vote" on her Brexit deal this week - saying one would be held by 12 March - but she will give MPs the chance to have their say on how the next steps for Brexit.
MPs will be able to table amendments to a government motion, putting forward their proposals on what they think should happen next.
Read more: Labour prepared to back new Brexit referendum - BBC News
Labour's Emily Thornberry said if the parliamentary process ended with a choice of no deal or the PM's deal, the public should decide.
Theresa May is under growing pressure to delay the 29 March Brexit date.
Labour have not yet made clear what their proposed referendum would be on, but a party briefing paper to MPs says that any referendum would need to have "a credible Leave option and Remain".
The prime minister, who will update MPs on the negotiations on Tuesday, has insisted the UK can still leave next month as planned.
The UK voted to leave the EU in a referendum in June 2016, but the withdrawal deal Mrs May negotiated with the EU has to be agreed by MPs - and it suffered a huge defeat by them last month.
Mrs May has ruled out a "meaningful vote" on her Brexit deal this week - saying one would be held by 12 March - but she will give MPs the chance to have their say on how the next steps for Brexit.
MPs will be able to table amendments to a government motion, putting forward their proposals on what they think should happen next.
Read more: Labour prepared to back new Brexit referendum - BBC News
