Rishi Sunak and EU Commission President Ursula von der Leyen are meeting in Windsor with hopes of thrashing out an agreement to tweak the Northern Ireland Protocol.
Those close to the talks have suggested a deal is on the brink of being signed, with the prime minister potentially revealing it to MPs as soon as this evening.
The Northern Ireland Protocol, which dictates how the UK and EU trade with Northern Ireland, has been causing problems for businesses, and the Democratic Unionist Party (DUP) is refusing to form a government until they are resolved.
Mr Sunak and Ms von der Leyen are hoping to agree a deal which eases the flow of trade between Great Britain and Northern Ireland, while also protecting the integrity of the EU’s single market.
Ahead of the meeting, the PM said the pair would discuss “shared, practical solutions to the range of complex challenges around the Northern Ireland Protocol,” and his EU counterpart said she is “looking forward to turning a page and opening a new chapter” with the UK.
But even if the pair do announce long-awaited changes to the protocol, Mr Sunak must win the support of the DUP so they agree to restore power-sharing in Northern Ireland to get Stormont back up and running.
He arrived for talks at the Fairmont Hotel in Windsor Park, Berkshire, shortly before 1pm, in an entourage of five cars accompanied by Metropolitan Police officers on motorcycles.
Ms von der Leyen will meet King Charles in Windsor following talks with Mr Sunak, at the invitation of Number 10 – a move Downing Street was forced to defend.
Baroness Arlene Foster, the former DUP leader and first minister of Northern Ireland, said: “I cannot quite believe that No 10 would ask HM the King to become involved in the finalising of a deal as controversial as this one. It’s crass and will go down very badly in NI.”
The prime minister’s spokesman said “it’s not uncommon for His Majesty to accept invitations to meet certain leaders” and it is “fundamentally a matter for the palace”.
Asked why the final protocol talks were taking place in Windsor, the spokesman said: “There are a number of occasions when these sorts of talks have been held in significant locations, this is no different.”
Prime Minister Sunak has been criticised for conducting talks without consulting the DUP and Eurosceptics within his own party.
He will need the approval of both groups if his Northern Ireland Protocol deal is to pass the House of Commons without relying on Labour votes.
The DUP has said it will not accept any deal which sees Northern Ireland continuing to follow any of the European Union’s rules, as the protocol currently dictates.