Theresa May is making a last ditch bid to save her Brexit deal after suffering a crushing defeat in a Commons vote on it.
Britain is still on course to leave the EU, but nobody knows whether it will be with a deal or not, or whether there will be a general election or a second referendum.
But here are some alternative ideas that a few weeks ago seemed highly unlikely but which could, in these extraordinary times, start to look like contenders.
Cancel Brexit
The European Court of Justice has ruled that Britain can revoke Article 50 of the Lisbon Treaty - the legal mechanism taking the country out of the EU on 29 March - without the approval of the other 27 member states.
This turns previous assumptions about Brexit on their head, and gives hope to those who believe it has all been a terrible mistake.
There is some debate over how the government would go about cancelling Brexit. Some argue an Act of Parliament would be needed, others say a Commons vote would be enough.
Given the divided state of Parliament, it is hard to see how any prime minister could get backing for such a move without a further referendum.
It would be seen by many MPs as a betrayal of the 17.4 million people who voted for Britain to get out of the EU in 2016.
Theresa May ruled it out on these grounds when asked about the European Court ruling by Plaid Cymru's Liz Saville Roberts.
European Council President Donald Tusk has hinted that cancelling Brexit would be his preferred option, tweeting, after Mrs May's deal was defeated by 230 votes: "If a deal is impossible, and no-one wants no deal, then who will finally have the courage to say what the only positive solution is?"
Senior backbenchers take control
This is a scheme dreamed up by Conservative backbencher and former minister Nick Boles, and two Conservative colleagues, Nicky Morgan and Sir Oliver Letwin, who want a softer version of Brexit than the one being promoted by Theresa May.
They have put forward legislation, the European Union Withdrawal Number 2 Bill, that would give the government three weeks to seek a compromise that can get through the Commons and allow the UK to leave the EU on 29 March as planned.
But if they fail to get the European Union Withdrawal Number 2 Bill through the Commons (and there is little sign so far of widespread support for it), they will push for the House of Commons Liaison Committee to be given the job of coming up with its own compromise deal, which the government would be legally required to implement if approved by MPs.
The 36-strong Liaison Committee is made up of the chairmen and women of the Commons select committees and other parliamentary committees.
The committee meets periodically to give the prime minister a grilling on the issues of the day and has not previously been pressed into action to come up with policy ideas.
Its members span every shade of opinion on Brexit, from Conservative Remainers such as Sarah Wollaston, who chairs the Liaison Committee and the Health Committee, to veteran Eurosceptics such as Sir Bill Cash and Bernard Jenkin. There are also a smattering of senior Labour figures, such as Yvette Cooper and Hilary Benn, two SNP MPs and one Lib Dem, Norman Lamb.
Whether they could do a better job of agreeing on a Brexit deal than the cabinet is an open question.
Speaking before Mrs May's defeat, Ms Wollaston said she has not been consulted about the idea and warned that MPs "cannot take over conducting a complex international negotiation".
According to the Financial Times, Chancellor Philip Hammond told business leaders on a conference call on Tuesday night the government would not put any "obstacles" in the way of Mr Boles's plan.
"We have to reach out to MPs in the Commons first," the chancellor is reported to have said. "There is a large majority in the Commons that is opposed to no deal."
The Queen intervenes
With no apparent parliamentary majority for any one course of action - is it time to get the Queen involved?
In Britain's constitutional monarchy, this is not meant to happen. Her Majesty has always remained above the political fray and will, no doubt, want to stay that way.
But she is the only person who can invite someone to form a government and become prime minister.
And if Theresa May loses a no-confidence vote in the Commons later, then this power could come into play.
There will be a 14-day period during which the Queen could ask someone to form a new government if it was clear they could command the confidence of the House. That could be Labour or another Conservative government or a cross-party government.
The Queen would not be able to exercise her own political judgement - everything would depend on whether the would-be new prime minister is deemed to have a realistic chance of getting their laws through Parliament.
The nightmare scenario, for the Queen and her advisers, is where it's not clear who has the best chance of winning a confidence vote but different people are making competing claims.
If after 14 days, a new government cannot win a confidence vote, a general election will follow. There could be multiple confidence votes, or none, before the 14-day deadline.
One thing the Queen can't do anymore is dissolve Parliament and trigger a general election.
The monarch was stripped of that power by the 2011 Fixed-term Parliament Act.
A Citizens' Assembly
Brexit is not the only controversial issue to be put to a public vote recently - and some countries, such as the Republic of Ireland after a referendum on overturning to its ban on abortion, have turned to a "citizens assembly" to find a way forward.
In Ireland, the body was set up to advise elected representatives on a number of ethical and political dilemmas facing the Irish people. It is made up of 99 members chosen at random to broadly represent the views of the Irish electorate, and a chairman.
Citizens assemblies are meant to give their members time to learn about an issue through discussions led by experts and then reach a conclusion through a series of votes.
The Guardian newspaper backs a citizens assembly to sort out Brexit, arguing in an editorial that Parliament should have the right, if it chooses, to put the ideas it produces to a referendum.
Left-wing campaign group Compass backs a citizens assembly on Brexit, and their campaign is supported by Labour MP Liz Kendall, former Archbishop of Canterbury the Right Reverend Lord Williams and Blur front man Damon Albarn, among others.
Two referendums
A cross-party group of MPs, under the People's Vote banner, is pushing for another EU referendum.
But what would the question be? A direct "Remain or Leave" re-run of the 2016 vote? Leave with a deal or no-deal? Or a combination of the two, with potentially three questions?
Vernon Bogdanor, professor of government at King's College, London, has suggested the Brexit impasse could be resolved by holding a further referendum - then another one.
He wrote in the Guardian that two referendums could be held a few weeks apart - the first, a straight Leave or Remain choice.
Then, if Leave won, another vote on the terms of departure.
Former cabinet minister Justine Greening has suggested an alternative - one referendum offering three choices, with people getting a first and second preference vote.
A government of national unity
Could a cabinet made up of members of different parties, usually formed during a time of national crisis, offer a solution to the current parliamentary deadlock?
It may seem like a concept confined to the history books - stirring up memories of former PM Winston Churchill's wartime coalition government, or the 1930s national government led by Ramsay MacDonald, after being expelled by the Labour Party.
But it has been publicly floated as a way out of the Brexit stalemate.
Advocates of such an arrangement have included Tory pro-Remain MP Anna Soubry, who suggested Mrs May should reach out to the SNP, Plaid Cymru, Labour backbenchers "and other sensible, pragmatic people who believe in putting this country's interests first and foremost".
Her fellow Tory backbencher Sir Nicholas Soames, Churchill's grandson, also backed the idea back in July.
Both the Labour and Conservative front benches rejected the suggestion over the summer - but it was revived by Remain-supporting Conservative MP Nicky Morgan in a Commons debate on the government's scrapping of the vote on Theresa May's Brexit deal, in December.
Parliament must "get down to work" to "hammer out a deal," she told MPs.
Ramsay MacDonald's decision to form a national government was considered a betrayal by many in the Labour Party, in the early 1930s.
And the electoral battering suffered by the Lib Dems after going into coalition with the Conservatives in 2010 will still be fresh in many minds.
A Parliamentary Commission
A Parliamentary Commission, made up of senior figures from the Leave and Remain sides of the debate, to oversee Brexit, is another idea that has been raised by MPs.
There was a lot of talk about this in the immediate aftermath of the 2016 referendum. Heavyweight figures, including Nicola Sturgeon, Lord Hague, Sir John Major and Yvette Cooper backed it.
Michael Gove also had warm words about cross-party cooperation, and argued that "we should draw on wisdom from great minds outside of politics" as well.
The Smith Commission - set up in 2014 by ex-PM David Cameron in aftermath of the Scottish independence referendum to "convene cross-party talks and facilitate an inclusive engagement process" - was seen by some as a possible model.
It is probably far too late to set up such a body to oversee the UK's withdrawal from the EU, on 29 March.
But the idea might get some traction again if trade talks get under way after Brexit day or if the Brexit deadline is extended.
It might take some of the partisan heat out of the debate and head off the kind of parliamentary turmoil we have seen this week.
But MPs are not meant to tell governments what to do, just scrutinise the decisions of ministers and hold them to account. So the danger is it could end up being a talking shop with no real power.