British Prime Minister Rishi Sunak has struck a new deal on post-Brexit trade rules for Northern Ireland, gambling that the reward of better ties with the European Union is worth any discord it might cause within his own party.

A government source said Sunak had agreed the terms with European Commission President Ursula von der Leyen as they met at a hotel west of London. They will hold a joint news conference at 1530 GMT.

The agreement marks a high-risk strategy for Sunak who has been looking to secure a compromise and improve relations with Brussels – and the United States – without sufficiently angering the wing of his party most wedded to Brexit.

Sunak’s spokesman had earlier told reporters that the two sides were in “final talks and significant progress has been made over a number of weeks and months”.

The deal seeks to resolve tensions caused by the 2020 post-Brexit arrangements governing Northern Ireland, a British province, and its open border with EU member Ireland.

It remains to be seen, though, whether it will go far enough to end political deadlock in Northern Ireland and satisfy critics in Britain and the province.

The new agreement is expected to ease physical checks on goods flowing from Britain to Northern Ireland, and give the province’s lawmakers a say over the EU rules it has to implement under the complicated terms of Britain’s exit from the bloc.

London could also set some tax and state aid rules.

Its success could hinge on whether it convinces the Democratic Unionist Party (DUP) to end its boycott of Northern Ireland’s power-sharing arrangements. These were central to a 1998 peace deal which mostly ended three decades of sectarian violence in the British province.

Before word of a deal became public, DUP leader Jeffrey Donaldson said they would have some time to review the specifics before determining whether to accept it.

In order to catch up to the opposition Labour Party, which is currently well ahead in opinion polls, before the scheduled 2024 general election, victory would strengthen Sunak’s control over his Conservative Party and allow him to move past the most divisive topic on his agenda.

If he were to fail, he would likely face a revolt from the eurosceptic faction of his party, reigniting the intense ideological differences that have occasionally paralyzed the government since the 2016 EU referendum.