Here's our latest flowchart guide to what could happen.

Image source, PA

Business campaign group London First says it supports the intervention made by the CBI and TUC.

Its chief executive, Jasmine Whitbread, says: “We’re drifting into a worst-of-both-worlds short extension that fails to take no deal off the table and potentially only delays a disastrous outcome.

"The PM’s insistence that she will bring back her failed deal for a third vote, so close to the deadline, will provide zero reassurance to London’s businesses that the government has a plan that can get us out of this mess.

"Now is the time for clear leadership: we should stop the clock, revoke Article 50 and give Parliament time to find a way forward. And if it can’t do that, put the decision back to the people.”

Labour leader Jeremy Corbyn has discussed Brexit with reporters and says he's trying to construct a majority who can "bring about a resolution to this crisis".

Asked about a second referendum, he says his party is thinking about what proposals they'll put to Parliament next week.

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Adam Bienkov, UK political editor of Business Insider, says there's long been an assumption that somehow a no-deal Brexit would be avoided, but there's clearly no majority for Mrs May's deal - and MPs are moving away from it after her speech yesterday.

A lot of businesses have worked on no-deal plans but people should be under no illusion that they are ready for it, he says. The feeling is - if we are heading for a no-deal Brexit, let us know about it, he adds.

And much like the public, businesses are pointing the finger of blame in the government's direction, he says.

Businesses have been speaking out regularly but warnings are largely falling on deaf ears, he adds.

The president of the European Parliament is not keen on extending Brexit until the end of June, says our BBC Brussels reporter:

This map shows which parts of the UK have the highest concentration of people signing the petition to revoke Article 50.

Image source, UK Parliament

Image source, AFP/ Getty Images

Mr Umunna's Independent Group colleague Anna Soubry has also criticised Theresa May's statement, calling it "disgraceful and dishonest".

"It wasn't about bringing people together, it was actually about keeping that divide and I think it was all about Theresa May staying in power," she said.

"And the one thing this country is crying out for is people who will put the country first and lead and show direction."

Arriving at the Cabinet Office for talks with minister David Lidington, Independent Group spokesman Chuka Umunna said it was "absolutely right" that the government was trying to bring opposition groups together.

"This is a national political crisis, this is perhaps one of the most serious situations our country has faced since the Second World War, there is impasse in the House of Commons, so it's absolutely right that the government and the prime minister are trying to bring representatives from different opposition groups together to try and find a way forward."

He added that he was "extremely disappointed" the PM had not heeded calls to bring the country together sooner.

He described her televised statement to the nation yesterday evening as "disgraceful" for the way it set the Executive against Parliament against the people.

"That is not the behaviour of a prime minister who is serious about pulling the country together in a time of crisis," he said.

If the EU agrees to a Brexit deadline extension then it should be as short as possible to protect the principles and functioning of the European institutions, according to French President Emmanuel Macron.

If it was too long it could "taint" the EU's ability to act and make decisions, he said.

Image source, EPA

Irish Prime Minister Leo Varadkar and Theresa May have held a short bilateral meeting in Brussels ahead of a meeting of EU leaders.

An Irish government spokesman said the pair discussed how matters might unfold over the next few days, including at this evening's European Council meeting.

Image source, UK Parliament

A petition on the UK Parliament's website - demanding Brexit be stopped - has passed a million signatures.

The petition calls for Article 50 of the Lisbon Treaty - the legislation which triggered Britain's withdrawal from the European Union - to be revoked.

So many people were signing it earlier today that part of the website crashed.

In the referendum three years ago 17.4 million people voted to leave the European Union.

In their joint letter to the prime minister the CBI (Confederation of British Industry) and TUC (Trades Union Congress) have urged Theresa May to change her approach to Brexit.

“We cannot overstate the gravity of this crisis for firms and working people,” they say.

"Firms and communities across the UK are not ready for this outcome.

"The shock to our economy would be felt by generations to come."

They say avoiding a no deal is "paramount" and that securing an extension is "essential.

They call for an Plan B that:

• Protects workers, the economy and an open Irish border,
• commands a parliamentary majority,
• and is negotiable with the EU.