At last, a Brexit deal is in sight

when it plainly isn’t,” the source said. “Hopefully, as long as MPs are kept fully informed, they will stay supportive.”

British negotiators are relieved that EU Council President Donald Tusk has tabled a discussion at the summit on backing the UK in the stand-off with Russian President Vladimir Putin over the nerve agent attack in Salisbury. They believe the move is a signal that claims from Remain campaigners and Eurocrats that Brexit would rupture European co-operation on defence and security will prove unfounded. “The discussion on Russia will be a significant moment,” the source said.

Mrs May’s team is looking forward to getting the transition deal done at the summit so the talks can focus on the far more crucial issue of Britain’s future trading partnership with the EU. “We feel we’re in a good place at the moment,” the source said. “It will be a relief to get the transition discussion out of the way at last.”

Agreement at the summit’s conclusion on Friday will mark another significant diplomatic achievement for the Prime Minister in a negotiation many of her critics claimed would prove so intractable it would break her premiership.

The process is proving that, behind the puffed up threats of punishment from the posturing Mr Juncker and Mr Barnier, the two sides have most to gain by working together.

MRS May’s progress in the talks is also raising morale among her inner circle. “It suddenly does not seem too unrealistic to talk about the Prime Minister leading the party into the next election,” one senior ally of Mrs May told me. Going back to the egg in Brussels this week looks like another sign of the rebirth of the Prime Minister’s long-term political prospects.