What is really going on in politics? Get our daily email briefing straight to your inbox Sign up Thank you for subscribing We have more newsletters Show me See our privacy notice Invalid Email

Jeremy Corbyn has dropped a political hand grenade into the Brexit debate that could change the course of history.

In a bombshell letter 50 days before Brexit, the Labour leader has shifted his red lines and offered Theresa May a clear way to leave the EU - if she backs a full 'customs union'.

It means if she accepts his demands, Mrs May can get a House of Commons majority for Brexit.

But firstly, that's a huge 'if' that could split the Tories.

Secondly, it throws a huge spanner in the works hours before the Prime Minister meets EU chiefs in Brussels today.

And thirdly, it's enraged some Labour MPs who want Jeremy Corbyn to stop helping the government push through Brexit - and back a second EU referendum instead.

All that means it's a long shot, and probably won't happen. But it's still an important intervention in Brexit.

So what is new today, how has Labour changed its position, and why are Remainer MPs angry?

Here's our guide - and the letter in full.

What is Jeremy Corbyn's offer?

(Image: PA)

Labour's leader has written a letter to Theresa May, saying he WILL back her on a Brexit deal if it meets five demands:

A permanent, UK-wide customs union with the EU

Close alignment with the EU single market

Dynamic alignment on rights and protections, so UK standards keep pace with new ones in the EU

so UK standards keep pace with new ones in the EU Clear commitments on participation in EU agencies

Unambiguous agreements on future security

Mr Corbyn has already held talks with the Prime Minister and more are expected to follow.

He promises to discuss his proposal with her in a "constructive" way to secure a "sensible agreement".

He says "compromise" is now needed to please both the EU and the House of Commons, which voted down the 585-page Brexit deal by a record majority last month.

How has his position changed?

(Image: Jack Taylor)

Labour already backed a customs union. But this change in tactics is vital.

Firstly, the letter means Labour has officially ditched its six tests a Brexit deal would have to meet before being backed.

The tests were unveiled in March 2017. They were based partly on Tory promises about Brexit, but included ambitions that were obviously impossible - such as securing "the exact same benefits" the UK currently has.

They were derided as "bollocks" by Shadow Trade Secretary Barry Gardiner.

Today the very same Mr Gardiner told the BBC: "It's not about tests now.

"What we are doing is saying we believe that these are the options that are available that would actually secure a majority in the House of Commons."

Secondly, it means Labour is putting calls for a second EU referendum firmly on the back burner - despite huge pressure within the party.

Labour pledged to keep a second EU referendum as an "option on the table" thanks to a motion at the party conference last year.

Remainers say Labour should campaigning for that public vote NOW, having failed to force a general election. But Jeremy Corbyn is against it.

Shadow Brexit Secretary Keir Starmer was forced to intervene after a backlash, insisting the Labour leader's letter did not take the prospect of a public vote off the table.

Thirdly, there is no mention in the letter of delaying Brexit. Labour has said extending the March 29 date may be inevitable. But this shows the party is still striving to help get a soft Brexit through as soon as it can.

Why are some Labour MPs furious?

(Image: Leon Neal)

Labour Remain-backers have voiced their fury at Jeremy Corbyn for - in their words - "enabling" Brexit.

They want him to back a second EU referendum instead.

And the words of Shadow Trade Secretary Barry Gardiner, who quoted Theresa May herself, won't help.

He said: "Jeremy is trying to set out what we believe is needed to make a success of Brexit."

Labour MP Chuka Umunna blasted: "This is not opposition, it is the facilitation of a deal which will make this country poorer.

Labour MP Owen Smith said he was "considering" quitting the Labour Party.

Fellow Remainer MP Chris Leslie said: “Seriously? Offering to help Tory Govt enable Brexit?

"It’s not just Labour’s conference policy in the bin. When the jobs go & revenues for services dry up as a result, Labour’s leadership will have ZERO right to complain: they share responsibility.”

Labour MP Tonia Antoniazzi wrote sarcastically: "Nice to be briefed about this @UKLabour @WelshLabour.

"If at ANY point you would like to consult MPs and also take the Labour Party conference motion into consideration... Just let me know... Cheers..."

Why is it a game changer?

(Image: Getty Images Europe)

For the first time, it means Theresa May doesn't need tochange the 'backstop' - or appease Tory Brexiteers - to get her deal through.

The backstop is an insurance clause that would trap the UK under EU customs rules from 2021, in exchange for keeping the Irish border open.

The Prime Minister is meeting EU chiefs in Brussels today to try and tweak the clause.

She's done that because Tory Brexiteers said otherwise, there's no way they would pass the Brexit deal. Yet EU chiefs say they won't change the backstop, leaving talks deadlocked.

Now Labour claims it has a way out by offering that permanent customs union - arranged, crucially, through the 'future framework' and not the 585-page exit deal that contains the backstop.

If she backs it, Labour claims, Theresa May won't need Tory Brexiteer help to get a Commons majority.

Barry Gardiner said: "What we're saying is actually you can do this another way.

"What you can do is say let's look at the future political framework, and if the future political framework were agreed now between the EU and ourselves to be a customs union, then actually there's no problem at that point when you get to the end of the transition period, because you're already in a customs union and therefore you don't need the backstop."

But why is it still a long shot?

(Image: PA)

Theresa May has made clear she wants to be able to strike trade deals around the world.

If the UK is in a full customs union with the EU, she can't do that.

And Labour proposed a customs union before - only to be defeated in the House of Commons.

Even if she did fold and accept a customs union, the row over it could split Theresa May's party for good.

Tory Brexiteer Jacob Rees-Mogg once warned of a revolt the size of that over the Victorian-era Corn Laws.

There is one important upshot though. If Theresa May refuses Jeremy Corbyn's offer, he can reasonably pin the blame on her if it leads to a No Deal Brexit.

How has Theresa May replied today?

(Image: IAN VOGLER/DAILY MIRROR)

A No10 spokeswoman said: "The letter has been received and we will reply in due course.

"Many of our positions on many of the issues in the letter are well known.

"The PM's focus is on securing changes to the backstop. That's what she is focused on today."

But a No10 spokeswoman repeatedly declined to say Theresa May will put any specific proposals to EU leaders today to solve the deadlock.

She said: "She will be discussing the ongoing urgent work we have been undertaking since the vote to secure the changes that mean we can secure parliamentary support."

She added: "You know our position on the customs union and that has not changed."

No new meetings with Corbyn were confirmed as of 11am but Mrs May's door remains open.

What happens next?

(Image: Reuters)

Theresa May is meeting EU chiefs including Donald Tusk and Jean-Claude Juncker in Brussels today. They're likely to brush her off, a day after saying Tory Brexiteers who had no plan have a "special place in hell".

Then she's travelling to Dublin on Friday night for dinner with Irish premier Leo Varadkar. He's likely to brush her off too.

But in between and afterwards, there's a window for talks with Jeremy Corbyn and his top team about the offer.

David Lidington, her de facto deputy, said there would be a "channel" open to Labour.

She's unlikely to have a new deal ready by next week, meaning MPs will get a vote directing the way forward on February 14.

That could bind her hands, delay Brexit, or just leave us in more deadlock as time ticks down to March 29.

The letter in full

(Image: PA)

Dear Prime Minister,

Thank you for taking the time to meet last week to discuss the Brexit negotiation and our alternative approaches to finding a deal that can command support in Parliament and be negotiated with the EU.

There is, as was demonstrated last week, a clear majority in Parliament that no deal must now be taken off the table and that there can be no return to a hard border in Northern Ireland in any circumstance.

We recognise that your priority is now to seek legally binding changes to the backstop arrangements contained within the Withdrawal Agreement, as we discussed when we met.

However, without changes to your negotiating red lines, we do not believe that simply seeking modifications to the existing backstop terms is a credible or sufficient response either to the scale of your defeat last month in Parliament, or the need for a deal with the EU that can bring the country together and protect jobs.

As you have said many times before, the EU has been clear that any withdrawal agreement would need to include a backstop to guarantee no return to a hard border on the island of Ireland.

Labour has long argued that the Government should change its negotiating red lines and seek significant changes to the Political Declaration to provide clarity on our future relationship and deliver a closer economic relationship with the EU. That would also ensure that any backstop would be far less likely to be invoked.

The changes we would need to see include:

* A permanent and comprehensive UK-wide customs union. This would include alignment with the union customs code, a common external tariff and an agreement on commercial policy that includes a UK say on future EU trade deals. We believe that a customs union is necessary to deliver the frictionless trade that our businesses, workers and consumers need, and is the only viable way to ensure there is no hard border on the island of Ireland. As you are aware, a customs union is supported by most businesses and trade unions.

* Close alignment with the Single Market. This should be underpinned by shared institutions and obligations, with clear arrangements for dispute resolution.

* Dynamic alignment on rights and protections so that UK standards keep pace with evolving standards across Europe as a minimum, allowing the UK to lead the way.

* Clear commitments on participation in EU agencies and funding programmes, including in areas such as the environment, education, and industrial regulation.

* Unambiguous agreements on the detail of future security arrangements, including access to the European Arrest Warrant and vital shared databases.

We believe these negotiating objectives need to be enshrined in law before the UK leaves the EU to provide certainty for businesses and a clear framework for our future relationship.

We recognise that any negotiation with the EU will require flexibility and compromise. Our first priority must be a deal that is best for jobs, living standards, our communities, in the context of increased and more equitable investment across all regions and nations of the UK. That approach should guide how alignment with EU regulations is to be maintained in future, as well discussions on dispute resolution, the role of the ECJ, and competition and migration rules.

EU leaders have been clear that such changes to the Political Declaration and a closer relationship are possible if such a request is made by the UK government and if the current red lines change. We believe that a close economic relationship along these lines would make it far less likely that any backstop arrangements would ever be needed.

The Government’s failure to secure a deal that can command the support of Parliament means time has run out for the necessary preparation and for legislation to be finalised. Following last week’s rejection by the House of Commons of ‘no deal’, all necessary steps must be taken to avoid such an outcome.

My colleagues and I look forward to discussing these proposals with you further, in the constructive manner in which they are intended, with the aim of securing a sensible agreement that can win the support of parliament and bring the country together.

Yours sincerely,

Jeremy Corbyn MP

Leader of the Opposition