BBC News Channel

The BBC's assistant political editor Norman Smith says the DUP's statement could be a "complete game changer" in the Brexit process.

"Although the DUP have suggested that it may just be a temporary disagreement, the issues at stake are really very profound indeed," he said.

"It might seem all a bit technical and finicky but it cuts to the very core of DUP beliefs around the union... and that is why this may prove a very fundamental stumbling block for Boris Johnson."

Today Programme
BBC Radio 4

Shadow Northern Ireland Secretary Tony Lloyd says Labour could back a confirmatory referendum on Boris Johnson's deal under some circumstances.

Previously the party has only said it supports another referendum putting a future Labour-negotiated deal against an option to remain in the EU.

But Mr Lloyd says if the prime minister's deal were set to pass in Parliament, the party would support an amendment to put it to a referendum.

He says: "We have to be very careful. Let’s just see what this deal is. Prime Minister Johnson has not yet chosen to show the British public in general what the deal consists of."

He says it is "fundamental" that the deal has no return to a hard border on the island of Ireland. But he says it is also important that there is "no erosion" of employment protections.

"If the PM can push through his deal, of course Jeremy Corbyn would accept that the best way through, rather than letting it slide through unchecked, it should be put to the test of public opinion," he says.

Chris Morris
BBC Reality Check

A revised Brexit deal, acceptable to both UK and EU negotiators, remains elusive.

Only a few people know exactly what has been discussed behind closed doors, and the legal text of any proposed agreement has not been made public.

But it's worth bearing in mind that most of the deal hammered out by Theresa May's government - the withdrawal agreement and the accompanying political declaration - would remain in place.

The main changes Boris Johnson's government wants to see concern the Irish border, and the type of relationship it wishes the UK to have with the EU in the future.

Read the full article here.

Sky News

Brexit Party chairman Richard Tice MEP said he would rather postpone the UK's departure date from the EU than hold another referendum.

He told Sky News' Kay Burley At Breakfast that his party "would never" support a second public vote because it would "destroy trust in democracy".

"It would infuriate the electorate, it would be divisive, it would be ugly," he said.

In the event a "clean break" from the EU was not possible on 31 October, he said: "We would rather [have] a very short extension so there could be a general election, and a Leave alliance could win a thumping majority and then leave on a clean-break Brexit because we would then have the numbers in the House of Commons."

Today Programme
BBC Radio 4

BBC political correspondent Ross Hawkins says MPs "are being taken away into quiet rooms" all over Westminster to gauge support for the deal.

The government is trying to win support of former Tories who rebelled against the party, Brexiteers who voted against Theresa May's deal, and Labour MPs who support leaving the EU.

Mr Hawkins reports that most Tory Brexiteers say their concerns have been addressed - but only a "very limited number of Labour MPs would come across".

MPs are not just being asked if they would support the prime minister's deal - they are also being asked if they would back no-deal. "That possibility remains very live," Mr Hawkins says.

Image source, PA Media

Brexit Secretary Stephen Barclay has just arrived at Downing Street.

He did not respond to questions about securing an exit deal.

BBC News Channel

Image source, House of Commons

Alistair Burt, an independent MP, says it is important to remember the DUP says its talks with the government are "ongoing".

"I do hope that the DUP will be able to come to a realisation to ensure that a deal gets put to Parliament and hopefully passed," Mr Burt says.

Mr Burt - who sits as an independent MP after losing the Conservative whip when he defied the government in a crucial vote - says he is "inclined" to vote in support of a deal that is approved by the EU.

Image source, AFP

The DUP named three issues with Boris Johnson's proposals - customs, consent issues and VAT. But what exactly are their worries?

Customs

The DUP is digging in over the prospect of a customs border between Northern Ireland and the rest of the UK.

The new back-up arrangements that would kick in under Mr Johnson's proposals would effectively see Northern Ireland following EU rules much more closely than the rest of the UK.

Consent

One of the key things that the PM has proposed is a way of giving Northern Ireland communities a say on whether or not to continue those arrangements.

But what the DUP has an issue with is that the mechanism that has been negotiated would give the suspended Stormont Assembly a final vote on whether to keep these rules going.

The DUP's concern is that might then mean that nationalists could keep Northern Ireland more tied to the EU than they would want, indefinitely.

VAT

Another major issue in the PM's proposals is whether or not EU VAT rates would apply in Northern Ireland - something the DUP says remains unclear, despite hours of talks with the government over the last few days.

Norman Smith
Assistant political editor

The decision by the DUP to reject Mr Johnson's deal is a potential body blow.

Not only would it seem to scupper the prime minister's prospects of securing a deal in Brussels today, but it also suggests he would be unable to win any subsequent vote in the Commons.

In their statement, however, the DUP do not quite close the door to a possible compromise in the future, implying that were there further concessions, they might be won around.

The DUP highlight the new customs regime and the issue of consent as the key sticking points.

However, it is understood issues around securing the consent of Stormont to the new customs regime have become paramount.

The fear in the DUP is that under the simple majority vote required by the EU to ensure continued membership of the new customs arrangement, the unionist community would have no veto.

So they worry they could remain trapped in an arrangement where increasingly the political and economic pull would be towards Dublin and Brussels, rather than London - threatening their core belief in the union.

BBC Europe editor Katya Adler reports that EU ambassadors expected to receive a draft of the new Brexit text this morning so they could read it with legal experts before leaders discuss it later today - but they haven't received it yet.

BBC News Channel

Housing Secretary Robert Jenrick says the government is still "optimistic" a deal can be struck, despite the DUP's current lack of support.

He says the government is working "very intensively" with the DUP and the EU to find a compromise to any concerns with the proposals.

"It's a very sensitive moment in the negotiations but we remain cautiously optimistic that because the parties still want to get a deal, there is a way through this," Mr Jenrick says.

He adds Mr Johnson is working "as hard as he possibly can to try to bring people together".

Adam Fleming
Reporter, Daily Politics

The opposition by the DUP throws into jeopardy the planned choreography of the summit, which would have seen Boris Johnson and the 27 other leaders approve a revised Brexit deal when they met this afternoon.

But the EU has been here before with Theresa May and knew that support for the deal at Westminster wasn’t guaranteed.

That’s why negotiators tried to address the concerns of the DUP and the unionist community in general in the new text of the agreement.

But the EU says it could never give the Northern Ireland assembly an upfront veto on the arrangements coming into force in the first place. And that’s one of the DUP’s big demands.

Today Programme
BBC Radio 4

Dr Andreas Nick, a member of the German parliament for Angela Merkel's CDU party, suggests the unravelling of the deal is a familiar story.

He tells BBC Radio 4's Today programme: "To a certain extent we seem to be back to square one.

"We have been able to agree with the British government a number of regulations that were then put away by the inability of getting agreement within the UK."

Today Programme
BBC Radio 4

Mairead McGuinness, an Irish MEP, says it is a "bad start to the day" for Boris Johnson.

She points out that any new negotiations to the PM's plans in light of the DUP's rejection would have to happen outside of the EU summit - making it "unlikely" that any huge headway can be made there today.

"It's hard to see a draft legal text being agreed now in time for the [EU] leaders to give consideration to it," she adds.

Image source, Getty Images

Once again, arrangements to prevent a hard border between Northern Ireland and the Republic of Ireland have proved a sticking point in the Brexit talks.

Why is the border such a sensitive issue in terms of political, diplomatic, and security concerns - and what are the possible solutions?

BBC Northern Ireland's economics and business editor John Campbell breaks down the options.

Image source, PA Media

Currency markets have been reacting to every twist and turn of the latest Brexit negotations, and today is no different.

Within minutes of the announcement that the DUP could not support the prime minister's deal as it stands, the pound fell 0.5% against the dollar.

A pound was worth $1.2759.