Are we more or less likely to crash out now without a deal, after the Brexit delay agreed in Brussels?

We’re much less likely to crash out without a deal next week because the 29 March Brexit deadline has been removed.

The government still needs to change the date in the EU Withdrawal Act – the central piece of Brexit legislation – but it can do that next week with a device called a statutory instrument, which will require a vote in both Houses of Parliament.

That is overwhelmingly likely to go through, as only a small number of MPs, perhaps 20 or so, would prefer a no-deal Brexit to any delay at all.

However, exiting without a deal is still very much on the cards for 12 April if the PM’s deal is not passed. The EU27 gave her an automatic extension to 22 May if her deal goes through next week.

If it fails once again, they have built in a fortnight’s breathing space for her – or parliament, if MPs can seize control of the agenda – to come up with an alternative.

That could mean a renegotiation of the political declaration – the forward-looking bit of the deal – to point to a closer future relationship. Or it could mean deciding to plough ahead with a no-deal Brexit.

It will matter greatly what the prime minister herself decides to do if her deal is defeated. Senior Tories right up to her own cabinet colleagues profess not to know, and she sent mixed messages this week about her intention. On Wednesday she appeared to suggest she would rather resign than countenance a longer Brexit extension; then in Brussels in the early hours of Friday morning she suggested she would work with parliament on finding the way forward.

Will Theresa May definitely bring back her Brexit deal to be voted on in parliament next week?

That’s certainly what EU leaders are expecting – so much so they wrote it into their summit conclusions in Brussels. And May said explicitly in her press conference that the agreement underlined “the importance of the House of Commons passing a Brexit deal next week”.

Downing Street must first convince the Speaker that the change in the date, plus the so-called “Stormont Lock” it plans to introduce over regulatory changes in Northern Ireland, represent a significant enough difference in the deal for it to be put to MPs for a third time.

And they could still pull the vote, if May remained convinced it would be defeated by another significant margin – but they would then have to spell out a plan B, or at least point the way for parliament to decide on one.

What else could parliament do?

Monday will see MPs debate and vote on an(other) “amendable motion”, that the government was forced to table after it lost the second meaningful vote last week.

The cross-party group of parliamentarians who have been working together to avoid a no-deal Brexit, including Hilary Benn and Oliver Letwin, have already tabled an amendment that would allow MPs to seize control of the parliamentary timetable, usually one of the key powers held by the government, to make the time for a series of “indicative votes” on what should happen next.

MPs have several times declined the opportunity to support such efforts, with the last amendment defeated by a majority of two votes. But parliamentarians may feel emboldened by the EU27’s clear invitation for them to seek an alternative solution, not to mention enraged by what many saw as May’s strident anti-parliament rhetoric in her Downing Street broadcast on Tuesday.

There were strong hints on Friday, including from the Brexit minister Kwasi Kwarteng, that the government could also be preparing to facilitate some process of indicative votes itself in the coming days, rather than surrender control of the parliamentary timetable to backbenchers.

Is ‘common market 2.0’ still an option?

Yes. If there is some process of indicative votes, it would be likely to be one of the options under consideration. It would be most likely to win a majority if its supporters could find a way of overcoming differences with the Labour frontbench Brexit plan – something its advocates have been working hard on in recent days.

“Common market 2.0” or “Norway plus” would mean joining the European Free Trade Association (Efta), a group of four countries – including Norway – that have a somewhat looser relationship with the EU than full membership.

Members accept freedom of movement (subject to an “emergency brake” the UK could impose in the event of significant economic or social disruption) and are inside the single market, and therefore follow all EU regulations. Advocates of the plan say the UK would then seek to negotiate a customs deal, too, to maintain just-in-time supply chains and obviate the need for checks at the Irish border.

But because it is an off-the-shelf plan, rather than a bespoke future relationship of the kind May’s deal promises, fans say there would be no need for a lengthy and disruptive second phase of negotiations, and instead, the UK could be an Efta member within a few months.

Q&A Might the UK still take part in European parliamentary elections? Show At the moment there seems to be three likely Brexit outcomes: a no deal departure on 12 April, a departure on 22 May with Theresa May's deal, or a lengthy extension to the process. The EU is only likely to grant a long extension if there is a significant change in the UK's position. For example, calling a second referendum, holding a general election, or asking the EU to renegotiate the political declaration that accompanies the withdrawal agreement. If the EU were to grant an extension beyond 22 May, the UK would be required to hold and participate in the European Parliamentary elections, which would take place on Thursday 23 May.

What about a second referendum? Could Saturday’s march and petition make any difference?

A second referendum is another option MPs would be expected to consider in the short period available after May’s deal is defeated next week.

It would necessitate a longer delay to Brexit beyond 12 April so that a poll could be held.

The UK would also then need to participate in May’s European elections – something May has insisted would be unacceptable.

Parliament would have to decide what options would be on the ballot paper. Labour has insisted it will only back a referendum with a “credible” leave option available, so that its leave voters can support Brexit – May’s deal would not appear to fit the bill if it has been repeatedly and overwhelmingly defeated in parliament.

However, any indicative votes process could involve allowing MPs free votes, so the frontbench’s position might prove less important.

The petition calls for article 50 to be revoked altogether, an option that has little support in parliament – unless it appeared to be the only way to stop a no-deal Brexit, which would not be the case if the government opened the door to finding alternatives.

But Saturday’s march will send a strong message to MPs when they are weighing up the options in the coming days.

If May’s Brexit deal is voted down for a third time, can she survive?

The prime minister’s authority, already shattered after her deal was defeated overwhelmingly for a second time, is draining away by the day.

It is unclear whether she would feel it incumbent on her to resign if the vote was lost again – she didn’t when it was lost the first time, by 230 votes, or the second, by 149.

But she has little support left on either wing of her own party, with MPs openly discussing her departure date this week. She might decide to bow out – but judging by her past record, she might also cling on. Tory MPs have no means of challenging her until December, when the yearlong breathing space she gained when she won last year’s vote of no confidence in her expires.

If she resigned, would that mean a general election?

Not immediately. There would have to be a Conservative leadership contest, which would take several weeks at least, involving a series of run-offs among MPs at Westminster (there are a lot of potential candidates), and then a members’ vote.

The winner would automatically become prime minister, just as May did when Cameron resigned, and indeed Gordon Brown did when Tony Blair stepped aside.

However, any new leader would face intense pressure to seek their own, personal mandate, on their own distinctive manifesto. And, more importantly, governing in a hung parliament is extremely difficult. A new prime minister who fancied their chances, as May once did, might be tempted to roll the dice and try to win a clear majority.