Rishi Sunak and Ursula von der Leyen are set to sign off on a new post-Brexit deal for Northern Ireland.
The Prime Minister and the European Commission President will hold “final talks” in Windsor, Berkshire, on Monday before she will go on to meet the King.
But even if long-awaited changes to the Northern Ireland Protocol are agreed it is likely to be only the start of the most challenging week of Mr Sunak’s premiership.
He wants to win the support of the Democratic Unionist Party (DUP) so they agree to restore powersharing in Northern Ireland to get Stormont back up and running.
So what exactly is expected to be agreed as part of the deal?
Here are answers to some of the main questions about the Irish Sea trading arrangements:
What is the Northern Ireland Protocol?
Jointly agreed by the UK and EU, it was the part of the Brexit Withdrawal Agreement that dealt with the main obstacle in the divorce talks – the Irish land border.
To keep the border free flowing, London and Brussels essentially moved new regulatory and customs checks required by Brexit to the Irish Sea.
That has introduced red tape on trade between Great Britain and Northern Ireland, creating a headache for many businesses and enraging loyalists and unionists who claim the region’s place within the UK has been undermined.
There were some sporadic outbreaks of violence linked to the protocol following its introduction in January 2021, but they were not widespread or sustained.
How is the protocol linked to the political impasse at Stormont?
The powersharing institutions can only function with the co-operation of the largest nationalist party and largest unionist party.
The DUP has used its veto to bring down devolution in protest at the protocol.
Its boycott means a ministerial executive cannot function and the legislative assembly cannot conduct any business.
In the absence of ministers, civil servants are in charge of running public services but they are hamstrung in the decisions they can take and many laws and policy changes are unable to be progressed due to the political vacuum.
The DUP has made it clear it will only go back into devolved government if significant changes are delivered on the protocol.
What have the Government and the EU been doing to resolve the dispute?
The Government initially hailed the protocol as the breakthrough that “got Brexit done”, and then portrayed early trade disruption as “teething problems”.
