Theresa May will ask for only a short extension to article 50 after a revolt among Brexiter cabinet ministers and MPs, despite previous promises to MPs that the UK would face a long extension if they did not vote for her deal before Thursday. So what happens next?

Why has the prime minister decided to seek a short extension?

Pro-Brexit cabinet ministers including Andrea Leadsom, Liam Fox and Chris Grayling told May a long extension would not be acceptable to them, while anger among other MPs was also growing.

Tory MPs were expected to demand the prime minister appear before the 1922 Committee of backbenchers on Wednesday evening. There were also rumours some could demand her resignation on the floor of the Commons during prime minister’s questions.

On Wednesday morning, a Downing Street source sought to calm tensions. “The PM won’t be asking for a long extension. There is a case for giving parliament a bit more time to agree a way forward, but the people of this country have been waiting nearly three years now. They are fed up with parliament’s failure to take a decision and the PM shares their frustration.”

In her letter to the EU council president, Donald Tusk, formally seeking the delay, May said only that the time would allow her to ask the Commons again about her plan. She did not specify what would happen if the vote was lost.

Didn’t MPs already vote to extend article 50?

Yes, last week parliament opted overwhelmingly to request an extension to article 50, by 413 votes to 202, though eight cabinet ministers voted against it in a free vote. The motion was technically not legally binding.

However, the motion did not commit to seeking a long extension, only to seek a one-off extension until 30 June as long as the deal was passed.

Then it went on to say: “It is highly likely that the European council at its meeting the following day would require a clear purpose for any extension, not least to determine its length, and that any extension beyond 30 June 2019 would require the United Kingdom to hold European parliament elections in May 2019.”

Didn’t May commit to seeking a long extension if MPs did not pass the deal?

Both May and her de facto deputy, David Lidington, suggested that would happen. May told the Commons “a short technical extension is only likely to be on offer if we have a deal in place” and said otherwise it would need to be longer and include holding European parliament elections.

“If [the house] is not willing to support a deal in the coming days, and as it is not willing to support leaving without a deal on 29 March, then it is suggesting that there will need to be a much longer extension to article 50,” she said.

Lidington went further. “If the house has not come together around a deal by Thursday next week, the only viable extension would be a long one,” he said during the debate. “We would have to hold the European parliament elections, and the government would facilitate a process with the house to consider the potential ways forward to reach a majority.”

What has the EU said?

The European commission president, Jean-Claude Juncker, said on German radio on Wednesday morning that a decision on a delay to Brexit was unlikely at this week’s EU summit and the bloc’s leaders may have to meet again next week.

Juncker told Germany’s Deutschlandfunk radio: “My impression is … that this week at the European council there will be no decision, but that we will probably have to meet again next week.”

Donald Tusk, the European council president, said EU leaders would only agree a short Brexit delay if May’s deal was backed by the Commons next week, but that the EU would seek to avoid the UK crashing out without a deal until “the very last moment”.

However, it appears likely that Brussels does expect the government to request a lengthy extension if the deal fails again, to allow time for cross-party talks on a soft Brexit or a general election or second referendum.

What can MPs do now?

The shadow Brexit secretary, Keir Starmer, called an emergency debate on the status of the extension in the Commons on Wednesday, but Labour is torn over whether to attempt to force the prime minister to bid for a longer extension.

Instead, fresh efforts are likely to be made for parliament to seize control of the process on Monday – when MPs will get to vote on an amendable motion that the government must table in order to update the house on the state of the negotiations.

May is expected to hold another meaningful vote next week – which is also likely to be amendable. If that also fails, MPs have been promised the opportunity for a series of indicative votes on possible Brexit outcomes, including a soft Brexit or a second referendum. There is also the possibility that Jeremy Corbyn could attempt a second confidence vote in the government to try to force a general election.

Downing Street is convinced a third meaningful vote would meet the requirements of the Speaker, John Bercow, that it be substantially different. This is because documents agreed in Strasbourg before the last vote will be ratified by the EU this week and new assurances are to be made to the DUP that there will be no new obstacles to trade across the Irish Sea within the UK’s internal market. The context of an extension may also be enough to substantially change the circumstances when May attempts to bring the vote back to the Commons.