Jean-Claude Juncker tells the press conference that the deal includes a transition period until the end of 2020.

"I'm happy and relieved that we reached a deal but I'm sad because Brexit is happening," he adds.

Donald Tusk asks a rhetorical question - what has changed which means there is now a deal agreed today?

Two reasons, he says. Because "the new version of the deal has been positively assessed" by Ireland and the European Commission.

Mr Tusk adds: "What I feel today is sadness because in my heart I will always be a Remainer."

European Council president Donald Tusk is speaking to reporters to explain why the EU leaders have backed the Brexit deal.

Radio 4 PM

Brexit-backing Conservative MP Andrew Bridgen, who voted three times against Theresa May's deal, says he needs to "look at the detail" before deciding how to vote.

However he says the agreement is a "far better deal than Theresa May's original offer", adding: "the more I hear about it, the more I like it".

He does add though that without the support of the DUP, it will be harder for Tory MPs to back it.

As meetings finish on the first day of the summit, European Commission president Jean-Claude Juncker and European Council president Donald Tusk are due to give a press conference shortly.

Adam Fleming
Brussels reporter

The EU and UK have reached an agreement widely hailed by European leaders as a significant step. But the deal still has to get past the UK Parliament, so why does Europe appear so keen?

First, lots of it is the same

Ninety-five per cent of this revised deal is the deal agreed with Prime Minister Boris Johnson's predecessor, Theresa May, during two years of painstaking negotiations.

Citizens' rights. Money. Ongoing cases at the European Court of Justice. The data of EU citizens stored in the UK. Under this deal, they would all be secured.

Unveiling the deal, EU chief negotiator Michel Barnier said: "This text… provides legal certainty and certainty where Brexit creates uncertainty."

There's one reason. Here are four more.

The prime minister's team at Number 10 will "make themselves available" to MPs while he is in Brussels, a spokeswoman says.

Asked why his aide Dominic Cummings went to Brussels, she says: "He's one of the PM's advisers. And the PM takes a team of advisers with him to key events and trips."

Many on social media have remarked on Jean-Claude Juncker's stern tone to a member of the media who interrupted him.

"I'm speaking!" he said sharply, to which the journalist replied: "I'm sorry, I'm sorry."

Mr Juncker later turned back to the reporter he scolded and said: "You were saying?"

You can watch the moment at the one-minute mark here:

BBC presenter Philippa Thomas suggested it was perhaps the "tiredness talking".

Sam Gyimah, who last month left the Conservative party to join the Lib Dems, said he would not vote for the deal.

The MP for East Surrey said: “I will not vote for it, and the reason why I will not vote for it is, firstly, it is one country, two systems.

"There was no mandate in the referendum to break up the UK, and this essentially does that, which is why the DUP can’t support it.

“If Boris Johnson is really into consent and giving us a vote on these things, then why doesn’t he subject his deal to a confirmatory referendum and let the people of this country decide whether this is the future that they really want.

"We will be looking to bring forward some kind of confirmatory referendum on his deal at the earliest possible opportunity.”

Peter Barnes
BBC political analyst

Image source, Getty Images

The winning post for votes in the House of Commons is 320 if everyone turns up. (Seven Sinn Fein MPs don’t sit and the Speaker and three deputies don’t vote.)

There are currently 287 voting Conservative MPs.

The first thing the prime minister needs to do is limit any rebellion among them as far as possible.

Then, if the DUP won’t support his deal, he’ll need the backing from former Conservative MPs who are currently independents.

There are 23 of them – most will probably support the deal but not all of them.

That’s still not quite enough though, so he’ll also need the backing of some Labour MPs and ex-Labour independents.

On 29 March, when MPs voted on Theresa May’s deal for the third time, five Labour MPs backed it plus two ex-Labour independents.

This time it’s likely to be a bit higher than that because several MPs have said they would now back a deal.

All this still leaves the overall vote very close though. And there’s a possibility that some MPs could choose to abstain making it even harder to be sure what the final outcome will be.

Image source, Getty Images

There might be a deal, but there's still more to do. The EU leaders are currently discussing Brexit and here's what's coming up this evening and in the next few days:

17:30 BST: The exact time is still to be confirmed, but Donald Tusk, EU Council president, and Jean-Claude Juncker, European Commission president, will give a press conference. The pair will be joined by Irish Taoiseach Leo Varadkar and the EU's chief negotiator Michel Barnier.

Friday, 7.30 BST: The leaders arrive for the second day of the summit. According to Number 10, Boris Johnson will stay in Brussels for day two.

8.30 BST: Mr Johnson and the 27 other leaders of EU states begin a round table meeting.

Later in the day, there will also be another press conference.

Saturday: MPs will hold an extra sitting in the Commons on Saturday - which is very rare - and will vote on the deal.

Image source, PA Media

Sinn Fein's deputy leader Michelle O'Neill says she welcomes the fact a deal had been reached and that Stormont's consent would be provided on the basis of a straight majority vote.

"We were very clear to say that there could never be a veto afforded to the DUP," she says.

However, she says the party needs time to digest the details of the deal, and that she and her colleagues will discuss aspects of it with Ireland's deputy prime minister Simon Coveney later.

It remains Boris Johnson's plan to stay at the EU summit on Friday, a spokeswoman for the prime minister says.