A new Brexit deal will not be agreed tonight, a government source has told Sky News.
British and EU negotiators have been locked in talks in a bid to thrash out an agreement that leaders could sign off at a summit on Thursday.
But despite indications that a deal is potentially within reach, a breakthrough has yet to materialise.
Boris Johnson told his cabinet earlier that “there was a chance of securing a good deal but we are not there yet and there remain outstanding issues”.
As well as updating his top team, the prime minister also held talks with Northern Ireland’s Democratic Unionist Party and the European Research Group of Conservative MPs.
The support of both groups will be key to getting any agreement passed in parliament.
On Thursday the focus will shift to Brussels, with the PM travelling to the Belgian capital for a gathering of fellow EU leaders.
Mr Johnson will use the European Council summit to try and get a deal over the line and bring back an agreement to present to MPs.
If he is successful, the stage will be set for a possible vote on an agreement during an historic sitting of the Commons on Saturday.
If not, the PM will have to ask for a delay to Brexit under the terms of legislation passed by opposition MPs.
Brexit Secretary Stephen Barclay earlier confirmed that scenario would see Mr Johnson write a letter to the EU asking for an extension to Article 50 beyond 31 October.
For now, the focus is on the potential for a deal.
EU sources have told the Reuters news agency that a tentative deal is largely ready, but “overall backing from the British government is needed to launch it all”.
The bloc’s chief negotiator, Michel Barnier, updated EU ambassadors on the state of play on Wednesday evening.
He said little to the waiting journalists as he left that briefing, saying simply: “We are working.”
Overall, the mood music from European leaders has been cautiously optimistic.
French President Emmanuel Macron said: “I want to believe an agreement is being finalised and that we will be able to endorse it tomorrow.”
Appearing at a joint news conference with German Chancellor Angela Merkel, he added that it was his hope that a deal “can be found in the coming hours”.
Ms Merkel declared: “We are in the final sprint.”
Irish Prime Minister Leo Varadkar said there was a “pathway to a possible deal”, but there remain issues that need to be “fully resolved”.
However, even if Mr Johnson returns from Brussels with a deal, there is no guarantee that MPs will pass it.
There are numerous groups that the PM will have to win round.
Perhaps the most vital is Northern Ireland’s Democratic Unionist Party – the DUP.
Leader Arlene Foster earlier poured cold water on suggestions that one of the main stumbling blocks to a deal – Northern Ireland consent issues – had been removed.
“Discussions continue. Needs to be a sensible deal which unionists and nationalists can support,” she wrote on Twitter.
The key issue that needs to be addressed is the issue of the Irish border.
Theresa May managed to negotiate a deal with the EU – but saw it rejected three times by parliament.
This was in large part due to the presence of the backstop in her deal.
This is an insurance policy designed to keep the frontier on the island of Ireland open in the event the issue cannot be sorted out before Brexit takes full effect.
Having come to office pledging to scrap the backstop from the withdrawal agreement, Sky News understands that Mr Johnson has in recent days proposed a compromise to try and break the deadlock.
The PM’s new proposal would replace the backstop, with Northern Ireland continuing to administer EU tariffs despite leaving the bloc’s customs union.
This would remove the need for customs checks but also allow businesses north of the border to benefit from new UK trade deals by applying for a rebate from the government.
The UK has reportedly agreed in principle that there will be a customs border in the Irish Sea, something the DUP has previously expressed opposition to.
If the DUP can be placated and brought on side, the majority of the ERG are likely to follow suit and back the agreement in a parliamentary vote.
Emerging from a meeting in Downing Street, ERG chairman Steve Baker said the group had made “great progress” in its discussions with Number 10.
“We know there will be compromises, but we will be looking at this deal in minute detail, with a view to supporting it,” he told Sky’s deputy political editor Sam Coates.
“But until we get that text, we can’t say.”
The backing of the 21 MPs who had the Tory whip withdrawn earlier this year for voting against the government on Brexit can also not be counted on for certain either.
One of them, former chancellor Philip Hammond, told Sky News he could vote for a deal – but needed certain reassurances on what kind of future relationship the PM would seek with Brussels after passing the withdrawal agreement.
Labour leader Jeremy Corbyn has said he is “deeply concerned” about the negotiations and has ruled out backing a deal under the PM’s reported terms.