Three years after the UK left the European Union (EU), the Conservative government has sealed an agreement with the bloc over the vexed issue of the post-Brexit trading rules in Northern Ireland.

The “Windsor framework” deal was secured Monday, after hundreds of hours of negotiations, and announced in a joint press conference by Prime Minister Rishi Sunak and European Commission President Ursula von der Leyen.

The deal amends the “Northern Ireland protocol”, which formed a crucial part of the Brexit deal former prime minister Boris Johnson signed with the EU in 2019. Painting the deal as all things to all people, Sunak declared, “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.”

Under the agreement, two new routes for goods will be introduced when they are travelling from Britain’s mainland into Northern Ireland. Goods passing through Northern Ireland destined for the Republic of Ireland—an EU member—must go via a “red lane”, ensuring they pass all customs checks they need to before crossing the Irish Sea. In a clause Sunak said would end “burdensome customs bureaucracy,” products set to stay in Northern Ireland—and therefore in the UK—will go via a “green lane”.

In a bid to win the support of the hardline Democratic Unionist Party (DUP), Sunak and the EU have agreed to give members of the Northern Ireland Assembly a say on any changes to EU law by offering them “the Stormont brake”. This will allow the UK, at the request of 30 members from at least two parties in the Northern Ireland legislative assembly, to oppose updates to new EU goods law in exceptional circumstances.

The deal Johnson put in place contained compromise arrangements to prevent a “hard border” on the island of Ireland, to allow trade flows from Northern Ireland to the Republic of Ireland. Preventing such a hard border was necessary to satisfy the provisions of the 1998 Good Friday Agreement, which ended three decades of armed conflict between the Irish Republican Army and its political arm Sinn Féin, and the British state forces and their Unionist and loyalist allies. 

The Northern Ireland protocol was opposed from the outset by the DUP. Replacing the external EU customs checks on trade from the North/South border to ports in Northern Ireland and the UK, the protocol resulted in significant problems and higher costs for business. By last year checks on goods from the UK at Northern Irish ports represented 20 percent of all checks at the EU’s borders.

The DUP’s opposition to the protocol was essential to its rejection of power sharing, over a year ago, with Sinn Fein in the devolved Northern Ireland Assembly and Executive. The DUP demanded the protocol be dropped before either institution could reopen and power-sharing resume.

The DUP set up “seven tests” under which any deal the UK government reached with the EU would be judged. These include cutting border red tape and giving the Stormont Assembly a veto over rules that apply in the region. The most frothing unionists will not sign up to any UK/EU deal. While not being in its tests, the DUP stressed as a London/Brussels deal edged closer that there is an end to the primacy of EU laws or no role at all for the European Court of Justice in Northern Ireland. On Sunday, the Daily Mail reported that DUP Chief Whip Sammy Wilson had told its reporters that “there should be no EU law applying to this part of the UK”.

The agreement also faces opposition from the Tories substantial hardline pro-Brexit European Research Group (ERG), with a rebellion by up to 100 of the ERG and other Tories being mooted as a possibility only a few days ago if the deal is put to a vote of MPs in Parliament.

Sunak is seeking to ensure that a rebellion is kept down to between 20 or 30 of his backbenchers. He is counting on a DUP majority supporting the deal, convincing most of the euro-sceptic wing of his own party to fall into line. Their mood was summed up by former Tory minister Sir Edward Leigh who told Sunak after the deal was announced, “I can assure him, many of his colleagues on these benches are watching the DUP very carefully, and we will go where they go… It all depends on our colleagues in the DUP. Because unless this exercise gets Stormont up and running, it’s pretty futile, indeed it might be downright dangerous.”

Sunak’s deal has the backing of some leading Brexiteers. As the Financial Times noted, “Steve Baker, Northern Ireland minister and self-described ‘hard man of Brexit’, scotched rumours he might quit, calling the pact ‘a really great deal’. David Davis, former Brexit secretary, also backed the agreement.”

A main player behind the scenes is the United States, which has crucial economic and political interests in ensuring a deal and stability on the island of Ireland. The US has long insisted that nothing must imperil the Good Friday Agreement it played a major role in securing, alongside the Blair Labour government, in 1998. As well as the Republic of Ireland, due to its status as a low tax haven, being a vital European hub for some of the largest US corporations; the Irish American lobby is a significant force in the ruling Democratic Party in the US.

Sunak also faces opposition from his predecessor Johnson, who is operating a campaign to undermine and hopefully replace Sunak as Tory leader. The Guardian noted Monday, “Although most Conservative MPs warmly welcomed the breakthrough after two years of negotiations, Johnson stayed away from the House of Commons chamber and is said not to have made up his mind about whether to endorse or oppose the ‘Windsor framework’”.

For weeks Johnson has publicly demanded that Sunak pass his stalled Northern Ireland Protocol Bill—giving the UK the right to unilaterally suspend aspects of the protocol in an emergency—which was drafted when Johnson was in office, in order to extract more concessions from the EU. However, the Sunday Times reported, “Privately, Johnson was more robust in an extraordinary confrontation in the Commons chamber with his former lord chancellor, Sir Robert Buckland, who lobbied Johnson to back the deal, arguing that it was necessary to cement relations with President Joe Biden. In a move that startled MPs, Johnson was overheard replying: ‘F*** the Americans!’”.

No vote is being held on the deal in Parliament this week, to allow the DUP’s 12 party officers to study the legal text and the Tories’ ERG to scrutinise it with the assistance of a “star chamber” of lawyers it is assembling. Sunak announced that MPs would “have a vote at the appropriate time”. DUP leader Sir Jeffrey Donaldson gave a guarded response, saying that while “significant progress” had been made, EU rules would still apply in Northern Ireland. He asked, “The key issue is why is EU law being applied and what is the purpose of that?”

It is highly likely that a vote in Parliament would pass the deal, as it has the backing of the main opposition Labour Party (with 196 MPs) in the 650-seat legislature. Speaking in Belfast last month, Labour leader Sir Keir Starmer said, “I say to the Prime Minister, if there is a deal to do in coming weeks, do it. Whatever political cover you need, whatever mechanisms in Westminster you require, if it delivers for our national interest and the people of Northern Ireland, we will support you. The time for action on the protocol is now. The time to stand up to the ERG is now.”

Starmer was a former leading Remain in the EU supporter, but has determined to accept Brexit—not least because he fears reopening divisions would politically destabilise the UK and prevent Labour taking office by again losing a substantial number of Brexit voting constituencies in the north of England.