Donald Trump walked away from the Iran nuclear deal purely to spite Barack Obama, a leaked memo written by the UK’s former ambassador to Washington claims.

Sir Kim Darroch described the move in the 2018 diplomatic cable as an act of “diplomatic vandalism”, according to a report in the Mail on Sunday newspaper.

The paper says the memo was written after then Foreign Secretary Boris Johnson appealed to the U.S. in 2018 to stick with the Joint Comprehensive Plan of Action (JCPOA) first announced to the world by Barack Obama on July 14, 2015. Sir Kim allegedly told Mr Johnson:

The outcome illustrated the paradox of this White House: you got exceptional access, seeing everyone short of the president; but on the substance, the administration is set upon an act of diplomatic vandalism, seemingly for ideological and personality reasons – it was [previous US president] Obama’s deal.

The latest leak came despite the Metropolitan Police warning against publication.

The paper also alleged Darroch hinted at discord brewing between Mr. Trump’s closest aides and said the White House had failed to produce a “day-after” plan on how to move forward after the deal was discarded.

The Iran accord, which is still backed by Britain, France and Germany, eased sanctions in return for cuts to Iran’s nuclear program. It was ended as part of a campaign promise by Mr Trump.

It is the second set of leaked emails published by he Mail On Sunday Last week they revealed Sir Kim had described Mr Trump’s administration as “inept” and “dysfunctional”, a revelation that eventually led to the ambassador’s resignation.

The Metropolitan Police Counter Terrorism Command, which is responsible for investigating allegations of criminal breaches of the Official Secrets Act (OSA), is investigating the source of the leaks.