Boris Johnson rewriting Brexit plan could damage UK's reputation, Theresa May warns

Fears other countries may not trust Britain after plan to break commitments in withdrawal agreement

Boris Johnson’s threat to unilaterally re-write parts of his Brexit agreement could damage Britain’s reputation abroad, Theresa May has warned. 

Speaking in the House of Commons on Tuesday the former prime minister said the government needed to “reassure” other countries that the UK would stand by its word in future agreements.

The concerns come ahead of a major push by Mr Johnson to strike trade deals with other countries around the world when Britain leaves the EU customs union at the end of the year.

“The UK Government signed the Withdrawal Agreement with the Northern Ireland protocol, this Parliament voted that Withdrawal Agreement into UK legislation,” Theresa May said in a debate following an urgent question on government plans.

"The Government is now changing the operation of that agreement. Given that, how can the Government reassure future international partners that the UK can be trusted to abide by the legal obligations of the agreements it signs?"

The government dramatically announced this week that it would pass new legislation on the Northern Ireland border that appears to conflict with its obligations under the withdrawal agreement. 

The government denies its new policy breaks the treaty, but European Commission Ursula von der Leyen on Monday reminded Mr Johnson that he had “an obligation under international law” to stand by the agreement, struck last year.

Asked if Mr Johnson now regretted signing up to the withdrawal agreement and its Northern Ireland protocol, the prime minister’s official spokesperson said “No”.

He insisted that the government remains committed to implementing both, despite the upcoming legislation which will allow UK ministers unilaterally to override measures agreed with Brussels.

The spokesman said: “We signed up to the protocol in the belief that its ambiguities would be resolved this year at Joint Committee. That may still happen.

“We hope an agreement is still possible but as a responsible government we can’t allow temporary default positions to kick in.”

The spokesman said that Mr Johnson had previously “publicly ruled out” the implementation of a number of provisions contained in the withdrawal agreement reached with Brussels.

“The prime minister has publicly ruled out export summary declarations on goods moving from Northern Ireland to Great Britain and tariffs on goods moving from Great Britain to Northern Ireland on several occasions,” said the spokesman.

“He did that in advance of the withdrawal agreement being agreed with the European Union.”

Under the withdrawal agreement, the UK has agreed to sign up to implement the EU customs code in Northern Ireland. The code includes so-called “exit summary declarations” – effectively paperwork that traders must fill out when they export goods. Despite agreeing to implement the code, the UK government now says these should not be required. 

During the general election Boris Johnson claimed the withdrawal agreement would not impose new paperwork on Northern Irish businesses exporting to Great Britain, which is not true.