The <a href="https://www.thenationalnews.com/tags/uk/" target="_blank">UK</a> and <a href="https://www.thenationalnews.com/tags/eu/" target="_blank">EU</a> clinched a post-Brexit deal on Northern Ireland on Monday, aimed at ending a years-long dispute that has poisoned their relations and called peace on the island of Ireland into question. UK Prime Minister <a href="https://www.thenationalnews.com/tags/rishi-sunak/" target="_blank">Rishi Sunak</a> sealed what he called a “decisive breakthrough” with European Commission President Ursula von der Leyen at a hotel near the royal Windsor Castle. The two leaders hailed the opening of “a new chapter” in post-Brexit relations. “The United Kingdom and European Union may have had our differences in the past, but we are allies, trading partners and friends,” Mr Sunak said. Mr Sunak is expected to travel to Northern Ireland later and plans to speak to backbench MPs in the Commons. MPs are expected to get a vote on the deal, but Downing Street has not so far said when or how such a vote might take place. Mr Sunak faces a tough battle to sell the deal to his Conservative Party and to unionist MPs from Northern Ireland, who said they would take time to consider their stance. The deal will rewrite trade rules but has a far wider significance for peace and sovereignty on the island of Ireland, with the 25th anniversary of the Good Friday peace agreement looming large. Mr Sunak said he had achieved changes to a 2019 Brexit deal that would simplify food and medicine rules and boost relations between Britain and Northern Ireland. A system of “red and green lanes” will cut red tape for traders moving goods to Northern Ireland, Mr Sunak said. A new “Stormont Brake” will give the Northern Ireland Assembly a say over EU single market rules being applied to the province. It means the UK could block European laws at the assembly's request in what the EU said would be “the most exceptional circumstances”. In return, the UK is conceding that European judges will have the final say over the rules — potentially crossing a red line for some MPs. Mr Sunak has been given assurances that the European Court of Justice will only weigh in as a last resort. “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,” Mr Sunak said. Ms von der Leyen said the deal “protects the very hard-earned peace gains” of the 1998 deal. It came on the day the New IRA claimed responsibility for the shooting of an off-duty police officer. The so-called Windsor Framework “respects and protects our respective markets and our respective legitimate interests”, she said. Mr Sunak confirmed the Northern Ireland Protocol Bill would be dropped following the new agreement, explaining that the legal justification for it had lapsed. “Now that we’ve persuaded the EU to fundamentally rewrite the treaty texts of the protocol, we have a new and better option,” he told MPs in the Commons. The Prime Minister said the new agreement can start delivering “benefits almost immediately” for Northern Ireland. On the updated legal position for the bill, Mr Sunak said: “It says because we have achieved a new negotiated agreement which preserves the balance of the Belfast/Good Friday Agreement, the original and sound justification legally for the bill has now fallen away. “In other words, neither do we need the bill nor do we have a credible basis to pursue it. “As such, we will no longer proceed with the bill and the European Union will no longer proceed with their legal actions against the UK.” Conservative former prime minister Theresa May urged all MPs to back Mr Sunak’s deal. “The Northern Ireland Protocol negotiated and signed by the government in December 2019 adopted the European Union’s preferred proposal of a border down the Irish Sea," Ms May told the House of Commons. “Can I congratulate the Prime Minister and the Secretary of State for Northern Ireland and Foreign Secretary and all their teams for all the work they have done to achieve this negotiated settlement, which will make a huge difference. “Does he agree with me that the best move now is for everybody across this House to support this settlement, because that is what is in the best interests of all the people of Northern Ireland.” Hardliners were also angered by a meeting on Monday between Ms von der Leyen and <a href="https://www.thenationalnews.com/tags/king-charles-iii/" target="_blank">King Charles III</a>, which they said risked dragging the monarch into politics. Buckingham Palace said the meeting came at the government's request but that it was normal for the king to see visiting leaders. Many Conservatives have indicated they will not support the deal without approval from Northern Irish unionists. The devolved government in Belfast collapsed last year after the Democratic Unionist Party pulled out over the trade dispute, putting on hold the power-sharing at the heart of the 1998 pact. DUP leader Jeffrey Donaldson said the party would “take our time to consider the detail” amid questions over whether it will be persuaded to return to sharing power. Katy Hayward, professor of political sociology at Queen’s University Belfast, told <i>The National that </i>the best Mr Sunak could hope for was to win over moderate unionists. “The framing of this deal and the implication for Northern Ireland both politically and economically will be all-important in trying to convince those people that their concerns are being addressed,” Prof Hayward said. One unionist member of the Northern Ireland assembly, former Ulster Unionist Party leader Steve Aiken, said shortly before the announcement that there was “no trust” between the UK government and Northern Irish businesses. “They are talking over Northern Ireland, they are not talking to Northern Ireland,” Mr Aiken said of Britain and the EU. The compromise came after years of UK-EU wrangling on the Northern Ireland Protocol, described by European diplomats as the “Achilles heel” of their post-Brexit ties. The 2019 deal had sought to avoid customs checks at the Irish land border — which could reignite sectarian tension — by checking goods in advance at Northern Ireland's ferry ports. But Tory and unionist MPs said the checks were excessive and undermined British sovereignty over Northern Ireland. Britain drafted legislation to unilaterally scrap parts of the protocol, prompting the EU to launch legal action, but hopes of a deal had been rising after diplomats spoke of a better atmosphere. One EU official said it was “clear that since Rishi Sunak became PM the mood has become much better and our work has become more constructive”. Ireland said it welcomed a “genuine response” to concerns and said it hoped the announcement would “allow the EU and the UK to open a new chapter”. US President Joe Biden has called Mr Sunak’s Brexit deal with the EU crucial to protecting the Good Friday Agreement. Mr Biden praised the efforts of London and Brussels to secure the deal. He said the deal was an “essential step to ensuring that the hard-earned peace and progress of the Belfast/Good Friday Agreement is preserved and strengthened”. “I appreciate the efforts of the leaders and officials on all sides who worked tirelessly to find a way forward that protects Northern Ireland’s place within the UK’s internal market, as well as the EU’s single market, to the benefit of all communities in Northern Ireland," Mr Biden said. “I am confident the people and businesses of Northern Ireland will be able to take full advantage of the economic opportunities created by this stability and certainty, and the United States stands ready to support the region’s vast economic potential.” Mr Biden’s backing is a significant boost for Mr Sunak. The US president has long taken a close interest in the peace process in Northern Ireland and has spoken often about his own Irish heritage. There are hopes that success in resolving the protocol row could lead to a visit from Mr Biden as part of events marking the 25th anniversary of the Good Friday Agreement. “Northern Ireland can accomplish the extraordinary when its leaders work together in common cause," Mr Biden said. "And I hope, as we all do, that Northern Ireland’s political institutions are soon back up and running. "Those institutions embody the principle of devolved, powersharing, representative government at the core of the Good Friday Agreement. “As Northern Ireland prepares to celebrate the 25th anniversary of the Agreement in April, let us remember that ending decades of conflict was not easy or inevitable. "It required hard work and determination, and an unfailing faith that a better future was possible. “Today, an entire generation of young people has grown up knowing only possibility and growing prosperity — the hard-earned dividend of peace. "I am deeply proud of the role the United States has played for decades to help achieve, preserve, and strengthen that peace enshrined in the Agreement. “And I look forward to continuing to work closely with our partners in Northern Ireland, the governments of the United Kingdom and Ireland, and the European Union, to further that peace and prosperity.” French President Emmanuel Macron welcomed the deal between the EU and UK on the Northern Ireland Protocol. “The United Kingdom and the European Union have just reached an agreement on implementing the post-Brexit framework in Northern Ireland," Mr Macron tweeted. “I welcome this important decision, which will preserve the Good Friday Agreement and protect our European internal market.”