By Jason Groves and James Franey for the Daily Mail and Ross Ibbetson for MailOnline
In a dramatic intervention, the Prime Minister will try to thrash out the framework of a deal over dinner with European Commission chief Ursula von der Leyen.
It comes on the eve of a crunch EU summit in the Belgian capital, which the bloc’s top negotiator Michel Barnier had said would mark the final deadline.
Mr Barnier warned the chances of a deal are ‘very slim’, but Mr Johnson yesterday offered a significant olive branch by agreeing to scrap controversial legislation that broke part of the original Brexit deal relating to Northern Ireland.
The EU had said it would not sign an agreement if the legislation remained.
Boris Johnson will fly to Brussels tonight in a last-ditch bid to salvage a Brexit trade deal over dinner with European Commission chief Ursula von der Leyen
In another major concession the EU will be allowed to have officials stationed in Northern Ireland, a sticking point on which Britain had previously stood firm.
The DUP called it ‘unnecessary’ and ‘concerning’, while Brexiteers told The Daily Telegraph that they would be watching closely to see if Mr Johnson decides to cede further ground to Ms von der Leyen tonight.
But government sources said big gaps remained between the two sides on key issues – and warned that the PM could pull the plug on negotiations if no progress was made.
One source said the two sides were too far apart for a deal to be struck tonight. But Mr Johnson hopes the two leaders can identify a breakthrough which their negotiators can finalise in the following days.
‘The aim is to unlock things so they can give their teams the authority to keep going and finalise the issues,’ the source said.
‘But if they strike out and make no progress then that is going to be it – there is no point carrying on for the sake of it.’
Mr Barnier told MEPs this week that today was the final deadline for a deal, as it had to be signed off by leaders at tomorrow’s EU summit
There are also fears French president Emmanuel Macron could use this week’s summit to grandstand on his opposition to a compromise, effectively wrecking hopes of a deal
One Cabinet minister said: ‘None of us really know what is going on. Is he going because he thinks there is a chance that he can return victorious with a piece of paper?
‘Or does he already know it’s probably No Deal and just wants to be seen to be doing everything he can?
‘Either way, it is entirely his call. Everyone wants a deal, but no-one is pushing him to take it at any price. It is down to his judgment.’
There are also fears French president Emmanuel Macron could use this week’s summit to grandstand on his opposition to a compromise, effectively wrecking hopes of a deal.
Downing Street blamed Mr Macron for torpedoing talks last week by pressuring Mr Barnier into toughening his stance just as progress was being made.
Two EU diplomats told the Mail that the chances of a Brexit deal were ‘now out of Barnier’s hands’.
Mr Johnson said the situation was ‘very tricky’ but he hoped the ‘power of sweet reason’ could still clinch an agreement in the final days before the Brexit transition ends this month.
He acknowledged there may be a point where it was ‘time to draw stumps’ and accept that a deal was impossible.
Talks have stalled on the vexed issues of fishing access and the UK’s right to set its own destiny without having to follow EU rules after Brexit.
The EU is prepared to accept only modest cuts to its fishing quotas and wants them phased in over ten years.
Brussels is also demanding that the UK compete on a so-called ‘level playing field’ in future.
Mr Johnson is willing to guarantee the UK will not lower existing standards in areas such as state aid subsidies, workers’ rights and the environment, but Brussels also now wants the UK to adopt future EU regulations, and is demanding the power to levy ‘lightning tariffs’ if we diverge – an idea No 10 says is unacceptable.
Mr Johnson said: ‘Our friends have just got to understand the UK has left the EU in order to be able to exercise democratic control over the way we do things.
‘There is also the issue of fisheries where we are a long way apart still. But hope springs eternal, I will do my best to sort it out if we can.’
Mr Barnier told MEPs this week that today was the final deadline for a deal, as it had to be signed off by leaders at tomorrow’s EU summit.
But the EU yesterday played down his comments, and suggested that talks could carry on until the end of this month – and possibly even into next year.
Downing Street said the UK was willing to continue talks for ‘as long as we have time available’ – but ruled out any extension into next year.
Tory Eurosceptics urged Mr Johnson not to back down on the UK’s red lines tonight.
In a message to the PM on Twitter, former party treasurer Lord Ashcroft said: ‘At dinner in Brussels, grip your marbles tight, pour lead in your pencil, don’t go wobbly and don’t cross your stated red lines… good fortune.’
Former Brexit minister David Jones said a deal was now only possible if the EU gave ground.
‘We will never again allow our trade and regulatory policy to be dictated by other countries. A free trade agreement is one thing; subservience is another.