Boris Johnson under pressure to publish legal advice in Brexit row

Brussels warns it is ready to deploy ‘all measures at its disposal’ as UK threatens to override Northern Ireland protocol

Boris Johnson is coming under intense pressure to publish the legal basis for plans to override the Northern Ireland protocol, as the EU raised the spectre of an all-out trade war by warning it was ready to take “all measures at its disposal” in response.

Legal experts questioned foreign secretary Liz Truss’s assertion in the House of Commons that a proposed parliamentary bill, which would drive a coach and horses through the finely balanced agreement struck by Boris Johnson in 2019, is “legal in international law”.

And there was unease on the Conservative benches over the potential damage to the UK’s reputation if it is seen to be breaching its international obligations.

“MPs will want to see the legal advice and know it is sustainable and arguable before going ahead with this,” one former minister told The Independent. “We don’t want to be back in the same battle as we had with the Internal Market Bill, with ministers talking about breaking the law in a limited way.”

The row came as the scale of disruption caused by Brexit to trade across the Irish Sea was exposed by Marks & Spencer boss Archie Norman, who said that sending a lorryload of goods to the Republic now required eight hours to be spent on paperwork in order to deal with 700 pages of documentation, some of it in Latin.

Ms Truss said that the legislation – due to be published before the summer – would protect stability in Northern Ireland, not only by easing checks on goods arriving from mainland Britain, but also by removing the role of European judges and taking on new powers for Westminster on VAT and subsidies in the country.

But the move would blow a hole in Northern Ireland’s special status under the Brexit deal, which uniquely allows it to enjoy the benefits of the single market.

European Commission vice-president Maros Sefcovic said that any UK move to disapply elements of the protocol was “not acceptable”, warning that Brussels was ready to “respond with all measures at its disposal”.

And Irish foreign affairs minister Simon Coveney said he “deeply regrets” the UK move, which he said was contrary to the wishes of people and businesses in Northern Ireland.

The Conservative chair of the Commons Northern Ireland committee, Simon Hoare, confronted Ms Truss on the floor of the house, telling her: “Respect for the rule of law runs deep in our Tory veins. I find it extraordinary that a Tory government needs to be reminded of that.

“Could she assure me that support for, and honouring of, the rule of law is what she and the government is committed to?”

Mr Johnson claimed that the “higher duty of the UK government in international law” was to the Good Friday Agreement and the peace process, rather than to the deal he had struck with Brussels.

He said that the text of the protocol made clear the need to protect trade across the Irish Sea and the integrity of the UK internal market.

And he denied he wanted to scrap the agreement, saying: “Let’s fix it. We don’t want to nix it, we want to fix it, and we will work our hardest to do it.”

Diplomats in Brussels said it was too early to speculate on how the EU would respond to unilateral action from the UK, though it is thought that any action is unlikely to be triggered until Ms Truss’s legislation clears parliament.

But Catherine Barnard, a professor of EU law at Cambridge University, told The Independent that options would go right up to the termination of the UK’s post-Brexit zero-tariff zero-quota trade deal.

Article 779 of the trade and cooperation agreement allows this “nuclear” option to be deployed with 12 months’ notice, potentially thrusting the UK into a no-deal Brexit in the run-up to the general election expected in 2024.

There is no legal basis to the government’s argument that the Good Friday Agreement takes precedence over the provisions of the protocol under international law, said Prof Barnard.

“The mainstream view is that this is likely to be incompatible with international law,” she said. “It will certainly be incompatible with the UK’s withdrawal agreement.”

And the government’s former top lawyer Sir Jonathan Jones, who quit over the Internal Market Bill, said: “Unilateral changes which aren’t also agreed with the EU aren’t a ‘solution’ at all; certainly not any settled end state.

“Instead, they can only be the beginning of a much more difficult phase in our relationship with the EU, involving (almost certainly, but let’s see the analysis) a breach of international law, undermining of trust, and the prospect of a trade war and other reprisals.”

Ms Truss insisted that the UK’s preference remains a negotiated outcome with the EU, and invited Mr Sefcovic to London to discuss the way ahead. Government sources said the bill could be pulled if Brussels complies with UK demands during the course of its passage through parliament, which is expected to take several months.

But former Northern Ireland secretary Peter Hain told The Independent that the House of Lords would “put up a No Entry sign” to Ms Truss’s legislation.

Peers will not feel obliged to let through a bill which does not feature either in the government’s manifesto or this month’s Queen’s Speech, said Lord Hain.

“It looks more like playing politics than serious negotiation,” he said. “There will be a lot of senior judicial figures now in the Lords, as well as former secretaries of state for Northern Ireland, who will not like this, and I think we can expect significant cross-party opposition.”

Conservative former deputy prime minister Michael Heseltine told The Independent the move was “the worst manifestation to date of the deceptions of Brexit”.

“This is entirely Boris’s fault,” said Lord Heseltine. “He made promises that he was warned would not be deliverable, and he is now going to breach international law, and that is not something a British prime minister should do. It threatens Britain’s reputation as a law-abiding society.”