Brexit: Boris Johnson’s EU trade deal branded worst UK negotiation in at least 40 years

Government must learn from mistakes ‘or we will all pay’, warns Tony Blair’s former chief of staff

Boris Johnson’s Brexit trade deal with the EU has been branded the worst UK negotiation in at least 40 years by Tony Blair’s former chief of staff and the chief negotiator of the Good Friday Agreement.

Jonathan Powell said that a series of British blunders allowed the EU to get its way “on every major economic point” in the negotiation, while the UK was left with “a few sops” on state aid and the role of the European Court of Justice.

He urged Downing Street to learn from its missteps before embarking on proposed trade talks with countries like the US, as well as the “decades of permanent negotiation” with the EU which Brexit has made inevitable.

Writing for the Politico website, Powell warned: “We do not want our government to make the same mistakes again or we will all pay for it.”

Mr Powell, who was involved as a diplomat in negotiations on the return of Hong Kong to China and German reunification before taking a lead role in the Northern Irish peace process and later becoming David Cameron’s envoy to Libya, said the UK side made a series of fundamental errors in the Brexit talks.

“I have spent the last 40 years involved in international negotiations of one sort or another, and I have never seen a British government perform worse than they did in the four years of negotiations that concluded with the Christmas Eve Brexit deal,” he said.

“Leaving aside the rights and wrongs of Brexit, purely in terms of negotiating technique, it is an object lesson in how not to do it.”

Under Theresa May, the government was wrong to trigger the formal Brexit process in 2017 before working out its own position, and wrong not to develop a strategic plan for the negotiations, he said.

The UK “massively over-estimated the strength of our negotiating position” when dealing with its “larger and more powerful neighbour” and forfeited trust by threatening to renege on its agreement with Brussels on the Northern Ireland border, he said.

As a result of these mistakes, Britain had to “back down every step of the way” in talks with EU negotiator Michel Barnier and was constantly confronted with self-inflicted deadlines by which it had to concede ground or face severe economic damage.

Crucially, Johnson’s government “prioritised principles of sovereignty over economic interests”, putting “a theoretical concept we don’t actually want to use” ahead of practical benefits for the UK.

“In any international agreement, from the Nato treaty to the Good Friday Agreement, a state limits its sovereignty, but it usually does so in return for practical benefits,” wrote Mr Powell.

“With this agreement with the EU, we have done the opposite.

“We have defended the theoretical possibility of doing things we don’t actually want to do, like lower our environmental standards or support failing industries, in return for giving up measures that would increase our prosperity.”

The result was an agreement, sealed by Mr Johnson on Christmas Eve, ratified by parliament in the early hours of New Year’s Eve and due to come into effect at 11pm today, which delivers “mostly what the EU wanted”.

“It is worth learning from these failures in negotiation strategy because we are embarking on a series of trade negotiations with countries around the world,” said Mr Powell.

“If we want to do more than simply replicate existing agreements those countries have with the EU, we are going to have to do a lot better.”