Ex-PM Boris Johnson will fight to save Northern Ireland protocol bill

Rishi Sunak is on a collision course with Boris Johnson over his plans to overhaul Northern Ireland’s post-Brexit arrangements, amid a frantic diplomatic blitz to end the bitter dispute with the EU.

In the latest sign of the political danger Sunak faces as he attempts to reform the Northern Ireland protocol, it is understood that Johnson has become concerned that a successful deal will see the government ditch controversial legislation allowing the UK to unilaterally rip up some Brexit arrangements in the region.

With Johnson and the Tory right threatening to disrupt the deal, Keir Starmer told the Observer he was taking the extraordinary step of offering his party’s support in any parliamentary vote on the agreement, enabling Sunak to stop “scrambling around to appease an intransigent rump of his own backbenchers”.

There has been persistent concern among Sunak’s allies that Johnson could attempt to derail a compromise with Brussels. Keeping the Northern Ireland protocol bill, introduced by Johnson’s government and currently working its way through parliament, now appears to have become a key test for the former prime minister.

While government insiders are at pains to state that there is much work to do on the details of any deal, they have signalled that a successful outcome would mean the bill would not be needed. “If we can find a way to satisfactorily resolve the issues with the protocol then you wouldn’t need the bill,” said a senior official. “But we haven’t resolved them yet.”

Supporters of the legislation insist it would give the UK continued leverage over Brussels. A source close to Johnson said it was his view that “it would be a great mistake to drop the Northern Ireland protocol bill”.

The new threat comes as Starmer called on Sunak to sidestep his hardline MPs by winning a vote on a deal with Labour backing. “This is no time for political brinkmanship,” he said. “This situation has dragged on for too long, and the stakes are too high.

“My offer to the prime minister stands. If a deal is on the table, and it delivers for the UK, Labour will back it. He doesn’t need to go scrambling around to appease an intransigent rump of his own backbenchers who will never be satisfied with anything. Labour’s priorities are clear and uncompromising: country first, party second.

“Twenty-five years ago, politicians of all sides showed courage and leadership to strike a deal that many said would be impossible. They put people before politics. We owe it to the people of Northern Ireland to do the same again.”

Downing Street has not yet decided whether or not to put any eventual deal to a vote, preferring to wait until a full agreement is on the table. There are already warnings from inside the government and among the most pro-Brexit wing of the Tory party that Sunak will face a political backlash if he tries to secure the deal on the back of Labour support. If Downing Street opts not to hold a vote, some MPs are already threatening to engineer one.

One Whitehall insider said it would be “political suicide” for Sunak to rely on Labour. Meanwhile, a senior figure from the European Research Group (ERG) of Conservative MPs warned: “It weakens him considerably. It’s proof … that he doesn’t command his party. That would go down extremely badly in parliament, but it would also go down very badly with the wider party, who would see that he is in a weak position.”

Rishi Sunak meeting the US vice-president, Kamala Harris, at the Munich security conference on Saturday. Photograph: Reuters

While details of the deal have not yet been published, it would involve separating goods from Great Britain that are staying within Northern Ireland and ensuring they do not have to undergo routine checks. There are also concerns that Northern Ireland has no say over new rules and regulations coming from the EU.

While MPs have not yet seen any details of the agreement, one figure on the Tory right said it already appeared to be “half baked” and would not deal with fundamental sovereignty concerns held by many Tories and the DUP.

Appearing at the Munich security conference on Saturday, Sunak attempted to dampen expectations of an imminent announcement, warning that an agreement was “by no means done”. Speculation has been rife that a paper outlining the agreement could be unveiled this week. “There are still challenges to work through,” he said. “We have not resolved all these issues … No, there isn’t a deal that has been done, there is an understanding of what needs to be done.”

The prime minister used the conference to hold bilateral talks over Northern Ireland with European Commission president Ursula von der Leyen. Sunak met the five main Stormont parties in Belfast last week. However, the DUP warned his proposed deal did not go far enough in resolving its concerns.

Asked about the state of talks on Saturday, a European official said there was “some creativity” taking place, adding that the outcome was hopefully coming soon. The official said: “A decision has to be made on how to solve these technical issues because it is mostly about technical issues now.” The source added that recently “the atmosphere was different”.

Foreign secretary James Cleverly has been briefing senior European foreign ministers in Munich, leaving officials convinced that the big issues of sovereignty such as the role of the European court of justice had been solved.

Officials said some of the recent goodwill was being born out of the need for the EU and the UK to work together to stand up to Vladimir Putin. Sunak had taken the largest British delegation to the Munich conference since Brexit, reflecting his belief that the solution to the Northern Ireland protocol will open the way for the UK to cooperate much more closely and formally with the EU on security issues.