Theresa May and her cabinet are looking for ways to bring her EU withdrawal agreement back to the Commons for a fourth attempt at winning MPs’ backing.
The PM said the UK would need “an alternative way forward” after her plan was defeated by 58 votes on Friday.
MPs from all parties will test support for other options during a second round of “indicative votes” on Monday.
However, Conservative Party chairman Brandon Lewis said the government did not support any of those options.
Labour leader Jeremy Corbyn has called on Mrs May to change her deal or resign immediately, while Northern Ireland’s DUP – which has propped up Mrs May’s minority government – also continues to oppose the deal.
The government has so far failed to win over 34 Conservative rebels, including both Remainers as well as Tory Brexiteers, who say the deal still leaves the UK too closely aligned to Europe.
But a No 10 source indicated the prime minister would continue to seek support in the Commons.
They insisted efforts were “going in the right direction”, given the margin of defeat was down from 149 a fortnight ago.
MPs will hold another set of votes on various Brexit options in the Commons on Monday.
Mr Lewis told Radio 4’s Today programme: “The government’s position is very clear – we do not support these options. The government’s position is we believe the best way to respect the referendum is to deliver the deal.”
He said one of the voting options put forward, which supports staying in a customs union with the EU, would go against the result of the referendum and the Conservatives’ election manifesto.
The customs union allows businesses to move goods around the EU without checks or charges. Continued membership would bar the UK from striking independent trade deals after Brexit.
Nicky Morgan, a former cabinet minister and fellow Tory MP, said there may need to be a government of national unity to end the deadlock over Brexit.
She told Today: “It may well be that if you end up with a cross-party approach to finding a majority in the House of Commons, it might be that you need a cross-party approach to implementing it.
“There have been periods in our history when we have had national unity governments or a coalition for a very specific issue.”
There is every chance that the prime minister will again – with routes outside the normal boundaries – try to make a version of her Brexit deal the end result of all of this.
Despite a third defeat, despite the embarrassment of repeated losses, don’t imagine that she is ready to say a permanent farewell to the compromise deal she brokered with the EU or, straightaway, to her time in office.
There is still a belief in the heart of government that there could be a way round, perhaps to include the prime minister’s agreed treaty as one of the options that is subject to a series of votes that will be put in front of the Commons next week.
The aspiration, strange as it sounds, for some time now has been to prove to MPs that the deal is the least worst of all the options…
Mrs May has until 12 April to seek a longer extension to the negotiation process to avoid the UK leaving without a deal – which most MPs believe could harm business and create disruption at ports.
However, she said any further delay to Brexit was “almost certain” to involve staging elections to the European Parliament in May.
Downing Street later said this was not an “inevitability”.
Meanwhile, Leave voters registered their anger at the latest rejection, on the day the UK was originally scheduled to leave the EU.
Thousands gathered outside Parliament to protest against the delay, bringing traffic to a standstill.
And the Conservative former Attorney General Dominic Grieve, who has campaigned for a further referendum on the deal, is facing deselection after losing a vote of no-confidence in his Beaconsfield constituency.
The prominent Remainer, who remains an MP for the time being, clashed with his local Conservative Party over Brexit.
What happens next?
- Monday, 1 April: MPs hold another set of votes on various Brexit options to see if they can agree on a way forward
- Wednesday, 3 April: Potentially another round of so-called “indicative votes”
- Wednesday, 10 April: Emergency summit of EU leaders to consider any UK request for further extension
- Friday, 12 April: Brexit day, if UK does not seek/EU does not grant further delay
- 23-26 May: European Parliamentary elections
The withdrawal agreement is the part of the Brexit deal Mrs May struck with Brussels that sets out how much money the UK must pay to the EU as a settlement, details of the transition period, and the Irish backstop arrangements.
If Mrs May wants to hold another vote on the deal in Parliament, it has to comply with Commons Speaker John Bercow’s ruling that it can only be brought back with “substantial” changes.
This is why the government separated the withdrawal agreement from the political declaration – on the future relationship with the EU – for Friday’s vote.
Downing Street said Mrs May would continue to talk to the Democratic Unionist Party about more reassurances over the backstop – the “insurance policy” designed to prevent physical infrastructure at the Irish border.
The DUP says that by temporarily subjecting Northern Ireland to different regulations to the rest of the UK, the backstop would risk a permanent split.
Its Westminster leader, Nigel Dodds, told Newsnight: “I would stay in the European Union and remain, rather than risk Northern Ireland’s position. That’s how strongly I feel.”
After the result of the latest vote was announced, Mr Corbyn said: “The House has been clear, this deal now has to change.
“If the prime minister can’t accept that then she must go. Not at an indeterminate date in the future but now, so that we can decide the future of this country through a general election.”
Will European leaders accept a longer delay to Brexit?
Despite all the drama, the money and time spent by EU leaders on Brexit (summits, dedicated governmental departments, no-deal planning) and all the hard, hard graft put in by the EU and UK negotiating teams, Europe’s leaders are asking themselves what there is to show for it all.
Ongoing Brexit divisions in Parliament, in government and in Theresa May’s cabinet were on screaming technicolour display again last week.
EU leaders used to use the threat of a no-deal Brexit as a negotiating tactic (as did the UK). They now believe it to be a very real prospect.
That has led to a number of countries – notably France – questioning the logic of delaying Brexit for much longer.
They wonder if the UK will ever unite around a Brexit Way Forward – be it a softer Brexit, no deal or no Brexit.
Would a Brexit extension, allowing for a general election or a second referendum, really settle the issue, they ask?