The Liberal Democrat leader has been speaking to BBC News and says it's the "beginning of the end for Brexit".

Sir Vince Cable says Theresa May's "options are narrowing" and that while she "may perform a miracle in Brussels" there's "no evidence that is in prospect".

"One of the biggest steps is to take no deal off the table," he says. "She needs to take action to remove it.

"That can only be by stopping or postponing Article 50."

BBC Politics Live
BBC2's political programme

Shadow business secretary Rebecca Long-Bailey says if the government survives tomorrow's no confidence vote, "all options will be on the table", including the possibility of another referendum.

Pressed on what Labour's Brexit policy was, should it wins the vote tabled by Jeremy Corbyn, she tells BBC News the party would respect the result of the 2016 referendum and need to be given "the opportunity to negotiate with the EU".

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 HM 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.

Dominic Casciani
Home Affairs Correspondent

The reaction outside Parliament is something of a reflection of what’s going on in the Commons - a mixture of resignation, determination to fight on, glum faces and occasional jubilance.

A small gaggle with known links to far-right causes and groups sought to goad Remainers, who have been flying Union and EU flags all evening.

Their favourite chant was a recommendation of the area of anatomy where Remainers should stick their European stars flags. Cue police moving into position to keep them separated.

Mainstream Leavers were somewhat muted - unless they clearly supported exiting with No Deal - those I saw were pretty chipper at the prospect of leaving on 29 March.

But with Remainers also largely sombre, most people seemed to echo the question pouring out of the Commons: What on earth happens now?

Image source, Reuters

You can check out how your MP voted tonight by using the tool in our story here.

BBC Radio 5 live

Labour's Chuka Umunna thinks another EU referendum is the only way out of this parliamentary gridlock. The 'People's Vote' campaigner says he wants his party leader Jeremy Corbyn to swing behind this plan - claiming that if it won enough support at Westminster, this would allow for Article 50 to be extended - avoiding a "catastrophic" no-deal exit.

Former foreign secretary Boris Johnson has speaking to the BBC. He says:

Mr Johnson says the defeat has "given the UK a massive mandate" to "go back to Brussels" and say the current deal, including being "locked in the customs union", "won't work for us".

"That's what the House of Commons wants," he adds.

Asked if a no-deal was off the table, he replies: "Not at all."

He suggests "keeping the good bits" of the deal, getting rid of the backstop, and "actively preparing for a no deal" with enthusiasm.

Business and union leaders are calling for urgent action after the prime minister's Brexit defeat.

Dr Adam Marshall, director general of the British Chambers of Commerce, said:

Ian Wright, chief executive of the Food and Drink Federation, said:

London Chamber of Commerce and Industry chief executive Colin Stanbridge said:

Royal Institute of British Architects chief executive Alan Vallance said:

Carolyn Fairbairn, CBI director general, said:

Stephen Martin, director general of the Institute of Directors, said:

The DUP's Brexit spokesman Sammy Wilson says his party will support the prime minister in tomorrow's no confidence vote.

He tells BBC News the DUP wants to see a "change of policy" rather than a change of government and the EU must offer a deal that addresses the concerns of MPs.

Image source, Getty Images

The pound has recovered some of its losses after MPs voted to reject Theresa May's Brexit deal.

The vote opens up a range of outcomes, including no deal, a renegotiation of Mrs May's deal, or a second referendum.

Sterling was still down on the day by 0.4% to $1.279 after declines of more than 1%.

The currency slumped 7% in 2018 reflecting uncertainty about the terms of the UK's exit from the European Union.

Read the full story here.

BBC Radio 5 live

5 Live's Guy Kilty has been at The White Lion pub in Wrightington near Wigan to gauge the public feeling around the vote.

Ellie Furzeman, landlady at pub, said:

"I think that most of the public are just sick of the whole thing and the politicians are just going round and round in circles and they're never going to get to a solution.

"I voted to stay in Europe. I think it'll end up going back to a public vote. I don't see what else they can do."

Join the conversation - by text on 85058 or @bbc5live, external on social media.

Reality Check

Image source, Getty Images

Defeats in the order of 100-plus votes are very rare.

The three biggest government losses, according to the Institute for Government think tank, all occurred in 1924 when the minority Labour government of Ramsay MacDonald was defeated by margins of 166, 161 and 140.

The third biggest defeat also happened in 1924 when the government suffered a 140-vote defeat on its Housing Bill on 3 June.

Read more from Reality Check here.

BBC Radio 5 live

Theresa May will get the backing of Northern Ireland's Democratic Unionist Party in tomorrow's confidence vote, the party's Brexit spokesman Sammy Wilson tells 5 Live Drive.

Mr Wilson, whose party has a pact to support the Tories in key votes, says Theresa May's Brexit deal broke this arrangement - but that she has been "saved from the consequences" by the deal being voted down.

He says Mrs May should return to Brussels and demand a "free relationship" with Brussels - or prepare to leave with no deal.

BBC Politics Live
BBC2's political programme

Health secretary Matt Hancock insists Theresa May is still the "best person to lead this country", despite the decisive defeat of her deal.

Asked what the government's "Plan B" is he says, provided the prime minister wins the vote of no confidence, she will then engage with MPs from all sides to find a deal which can achieve a majority in Parliament.

Pressed on whether he could rule out an extension of Article 50 he says it is "not what I want to see" and doesn't believe it is "necessary".

That's what the prime minister had in November when dealing with the backlash to her deal.

But as Tina Daheley, host of the BBC's Beyond Today podcast, says, she may need more than that tonight.