Brexit: What happens now?
MPs have rejected Theresa May's Brexit deal for a second time by a majority of 149. That's a narrower defeat than the record 230 majority they inflicted on 15 January but it still leaves the question about what happens next wide open.
MPs will next vote on whether the UK should leave the EU without a deal. That vote is scheduled for 13 March.
If MPs vote against no deal, they would then go on to a further vote on Thursday 14 March on a Brexit delay.
So what happens if MPs back a delay? Theresa May would then request an extension to Article 50 from the EU.
Assuming the other member states all agreed, Brexit would be postponed. Theresa May says this should be for no longer than three months.
But what would happen then? There are still plenty of possible answers.
1. No deal at a later date
Delaying Brexit would not mean that leaving the EU without a deal was ruled out forever.
If the UK and the EU cannot sign off a deal during any extension then this would still be the default outcome.
So although a majority of MPs have indicated they are against no deal – something they could well repeat on 13 March – they would need to do something else to prevent it from happening as a matter of course.
2. Further vote on PM's deal
Probably the simplest course of action during an extension would be for Theresa May to have another go at getting her deal through the House of Commons.
Although by then it would have been rejected twice, there's no rule to say that she couldn't bring it back again.
If she could win approval for the deal at a later date, the process would be basically the same as now. Legislation would be introduced to bring it into effect with a new Brexit date.
3. Major renegotiation
The government could propose to negotiate a completely new Brexit deal.
This wouldn't be a question of carrying out minor tweaks and having a further vote.
Instead, there could be a complete renegotiation that would take some time.
The government could pivot towards one of the other models of deal that has been suggested – perhaps something close to the so-called "Norway model" which would involve a closer relationship with the EU than the current deal proposes.
If the EU refused to re-enter negotiations, the government would have to plump for one of the other options instead.
4. Another referendum
A further possibility is to hold another referendum.
It could have the same status as the 2016 referendum, which was legally non-binding and advisory – in common with past UK referendums. But some MPs want to hold a binding referendum where the result would automatically take effect.
Either way, a referendum can't just happen automatically. The rules for referendums are set out in a law called the Political Parties, Elections and Referendums Act 2000.
There would have to be a new piece of legislation to make a referendum happen and to determine the rules, such as who would be allowed to vote.
It couldn't be rushed through, because there has to be time for the Electoral Commission to consider and advise on the referendum question.
The question is then defined in the legislation.
Once the legislation has been passed, the referendum couldn't happen immediately either. There would have to be a statutory "referendum period" before the vote takes place.
Experts at University College London's Constitution Unit suggest that the minimum time for all of the required steps above is about 22 weeks.
5. Call a general election
Theresa May could decide the best way out of the deadlock would be to hold an early general election – in order to get a political mandate for her deal.
She doesn't have the power just to call an election. But, as in 2017, she could ask MPs to vote for an early election under the terms of the Fixed Term Parliaments Act.
Two-thirds of all MPs would need to support the move. The earliest date for the election would be 25 working days later but it could be after that – the prime minister would choose the precise date.
6. Another no-confidence vote
Labour could table another motion of no confidence in the government at any time.
Under the Fixed Term Parliaments Act 2011, UK general elections are only supposed to happen every five years. The next one is due in 2022.
But a vote of no confidence lets MPs vote on whether they want the government to continue. The motion must be worded: "That this House has no confidence in Her Majesty's Government."
If a majority of MPs vote for the motion then it starts a 14-day countdown.
If during that time the current government or any other alternative government cannot win a new vote of confidence, then an early general election would be called.
That election cannot happen for at least 25 working days.
7. No Brexit
The European Court of Justice has ruled that it would be legal for the UK to unilaterally revoke Article 50 to cancel Brexit (without the need for agreement from the other 27 EU countries).
With the government still committed to Brexit, it's very likely that a major event such as a further referendum or change of government would have to happen before such a move.
However, any delay to Brexit would certainly lead to questions about whether the ultimate destination was going to be a reversal of the 2016 referendum.
It's not totally clear what the process would be. But an act of Parliament calling for Article 50 to be revoked would probably be sufficient.
After Theresa May survived a challenge to her leadership, the Conservative Party's rules mean she won't face another for 12 months.
But she could always decide to resign anyway, if she can't get her deal through and she's not prepared to change course.
That would trigger a Conservative leadership campaign which would result in the appointment of a new prime minister.
She might also come under pressure to resign if MPs pass a "censure motion" – that would be a bit like a no-confidence vote but without the same automatic consequences. Again this could lead to a change in prime minister or even a change in government.
Whoever ended up in charge would still face the same basic range of Brexit options though.
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