Plan C, also known as the Malthouse Compromise, was created by rival factions - Conservative Brexit supporters including Jacob Rees-Mogg and Steve Baker, and leading Remainers including Nicky Morgan and Stephen Hammond.

According to a leaked document, the proposal would extend the transition period - during which the UK would continue to follow EU rules and pay into its budget - from the end of 2020 to December 2021, to allow more time to reach a free trade deal.

Today's Parliamentary debates could shape any future negotiations between the UK and the EU over Brexit.

Fifteen amendments, external to the governments proposals have been put forward by MPs.

The Speaker, John Bercow, will decide which will be debated - announcing his choices around 12:45 GMT. Then we will learn which, if any, have the backing of the House.

Voting will take place in the Commons from 19:00 GMT.

Amendments have been tabled by MPs from all the main parties, on everything from preventing a No Deal, to postponing Brexit, and dealing with the backstop.

Read more about the amendments here

Victoria Derbyshire

Lib Dem MP and former minister Ed Davey said it was now time for a cross-party group of MPs to "get a grip on this in the interests of the people".

He said that would probably mean extending the Article 50 negotiating period.

Crashing out without a deal would not only be a disaster but was not really a credible threat, he said.

"I think the Europeans think we're completely crazy, even threatening that. And I think in the real world of negotiation you've got to have credible threats."

Pro-EU Conservative former minister Anna Soubry, who backs the People's Vote campaign for a second referendum, has rejected the Malthouse Compromise proposals.

This would extend the transition period from the end of 2020 and in to December 2021 and allow the UK and EU to "prepare properly" for WTO terms or "obviate this outcome by negotiating a mutually beneficial future relationship".

Ms Soubry said: "We understand why MPs desperately concerned about crashing out of the EU are considering desperate measures but this latest proposal only heightens the risk of a no-deal outcome.

"The prospect of the EU ripping up the Withdrawal Agreement or allowing a transition period without the backstop is very remote - and for good reason given the risks to the Irish peace process.

"Instead, this scheme backed by Jacob Rees-Mogg is a recipe for the no-deal Brexit that the hard Brexiteers have always craved."

Katya Adler
Europe Editor

Image source, Getty Images

Boris Johnson insists on them, Graham Brady is pushing hard for them, Prime Minister Theresa May seems to be praying for them and Dublin is deeply worried at the thought of them but will the EU ever actually "give in" and make changes to the backstop - that guarantee post-Brexit to avoid a hard border between the Republic of Ireland and Northern Ireland?

It's a tough one.

The EU certainly never intended to budge on the backstop - painfully negotiated with the UK over 18 months and signed off last November by Mrs May and her cabinet.

But Europe's leaders didn't imagine the UK would still be in such flux over Brexit so very close to B-day on 29 March.

Read more from Katya here.

Tony Blair has reitereated his calls for a second referendum.

The former PM insisted it was "incredibly dangerous" for the UK to leave the EU without having cabinet in agreement over the future relationship with the EU.

He told an audience of UK business leaders at the Edleman Trust Barometer conference: "I think a second ref is the only way to go. The truth of the matter is, it's the only way to bring closure.

"Theresa May's strongest card at the minute is 'get this thing over and done with, turn the corner' - that's her strongest card.

"The problem is her deal doesn't turn the corner. You're going to be in the same stretch of road after March 2019 because you haven't changed the future relationship [with the EU]."

Theresa May's ministers have begun arriving at No 10 for this morning's cabinet meeting, ahead of the debate.

Image source, EPA

Image source, EPA

Image source, EPA

Image source, EPA

Image source, EPA

Image source, Getty Images

Labour MP Rachel Reeves has said her amendment aimed at preventing a no-deal Brexit would tell the government "we will not accept crashing out without a deal".

Her amendment requires the government to ask the EU to postpone Brexit day (without specifying for how long).

She said it was an opportunity to say to the prime minister and her government 'You have got a month left and if - in a month's time - you still can't get your deal through Parliament, you must seek that extension of Article 50 to avoid that catastrophic outcome'.

Ireland's European affairs minister Helen McEntee has called for "realism" from the UK and said that the Withdrawal Agreement and the backstop could not be renegotiated.

She said: "There can be no change to the backstop. It was negotiated over 18 months with the UK and by the UK.

"A bit of realism is needed at this stage."

Norman Smith
Assistant political editor

Image source, Getty Images

Labour leader Jeremy Corbyn is under "huge pressure" to back an amendment attempting to rule out no deal, the BBC's assistant political editor Norman Smith says.

"He is under huge pressure to back this no deal amendment from Yvette Cooper."

"To date, he has remained largely shtum about what he's going to do.

"This morning however, there is a meeting of the shadow cabinet where we are told clarity will emerge."

Labour backbencher Yvette Cooper has put forward an amendment to rule out the UK leaving the EU without a formal deal by allowing parliament time to pass a new law.

Today Programme
BBC Radio 4

Image source, AFP PHOTO /JESSICA TAYLOR

Later today, Speaker John Bercow will decide which amendments are put forward. But why don't they get picked further in advance?

Lord Lisvane, former clerk at the Commons, explains: "There's a logic about that.

"Because you can put down amendments until the House rises the previous evening. So the Speaker will need some time to think about which amendments to select.

"And, of course, it is entirely at his discretion."

He said the Speaker must consider whether some amendments would "fight" with others, or potentially prevent others from being called later on.

Today Programme
BBC Radio 4

Sammy Wilson, Brexit spokesman for the DUP, which props up Theresa May's government, is asked about one amendment -- the so-called Brady amendment - which proposes replacing the backstop with alternative arrangements to avoid a hard border in Ireland.

"We need to hear from the prime minister today certain assurances in the House of Commons, on - first of all - what kind of alternatives she intends to pursue - will it be radical alternatives?

"We don't simply want to have additions to the withdrawal agreement or assurances on the withdrawal agreement. We need to have this removed."

BBC Radio 5 live

Conservative MP Sir Graham Brady has tabled an amendment calling for Parliament to require the backstop to be replaced with "alternative arrangements to avoid a hard border" but would otherwise support the prime minister's deal.

Now the DUP has said it supports "sentiments" in the amendment, but still wants "certain assurances" from the prime minister about what alternatives she'll pursue.