British Prime Minister Rishi Sunak on Monday unveiled a “decisive breakthrough” in achieving a new deal with the European Union (EU) to resolve the post-Brexit trade dispute related to Northern Ireland.

After weeks of intensive negotiations, Sunak was joined by European Commission President Ursula von der Leyen for a final set of in-person talks in Windsor, south east England, after which the duo addressed the media to confirm a new “Windsor Framework”.

It replaces the previous Northern Ireland Protocol, agreed by Sunak’s former boss Boris Johnson to prevent a hard border between UK territory Northern Ireland and EU member-state Ireland but eventually proving unworkable and causing much tension between the UK and EU. “I’m pleased to report that we have now made a decisive breakthrough. Together we have changed the original protocol and are today announcing the new Windsor framework,” Sunak told reporters.

 “Today’s agreement delivers smooth-flowing trade within the whole United Kingdom, protects Northern Ireland’s place in our union and safeguards sovereignty for the people of Northern Ireland… and [removes] any sense of a border in the Irish Sea,” he said. Von der Leyen echoed Sunak’s optimism to say that the UK and EU can now open a new chapter in their post-Brexit relationship. They detailed “big steps forward” to deliver trade flow with goods destined for Northern Ireland travelling through a new “green lane” with a separate “red lane” reserved for items expected to move on to the EU.

“We will end the situation where food made to UK rules could not be sent to and sold in Northern Ireland. This means that if food is available on supermarket shelves in Great Britain, then it will be available on supermarket in Northern Ireland,” said Sunak.

The legal text of the Northern Ireland Protocol has been amended to ensure critical VAT and excise changes for the whole of the UK can be made and the devolved Northern

Irish parliament in Stormont would have a say on the changes. “These negotiations have not always been easy, but I’d like to pay an enormous personal tribute to Ursula for her vision in recognising the possibility of a new way forward... Today’s agreement is about preserving that delicate balance and charting a new way forward for the people of Northern Ireland,” added Sunak.

The British Indian leader now faces the uphill task of getting Northern Ireland’s Democratic Unionist Party (DUP) on board with the new Windsor Framework.

The DUP had been strongly opposed to the earlier protocol, which meant goods arriving from England, Scotland and Wales within the United Kingdom were checked when they arrived at Northern Irish ports. This was seen as undermining the region’s position within the rest of the UK, besides severely impacting trade.

The other group likely to make things difficult for Sunak in the House of Commons include the hard Brexiteers within the Conservative Party, including backbencher Johnson, who had warned against backing down over Northern Ireland Protocol Bill – which would have given the UK Parliament a chance to unilaterally change parts of the protocol.

However, Sunak had indicated that a fresh negotiated agreement with the EU was preferable over the controversial Bill that would have put the UK on a legal collision course with its European neighbours.