LONDON    -    A U.K. newspaper published more leaked memos from Britain’s ambassador in Washington on Sunday, despite a police warning that doing so might be a crime.

In one 2018 cable published by the Mail on Sunday, U.K. ambassador Kim Darroch says President Donald Trump pulled out of an international nuclear deal with Iran as an act of “diplomatic vandalism” to spite his predecessor, Barack Obama. The memo was written after then-Foreign Secretary Boris Johnson visited Washington in a failed attempt to persuade the U.S. not to abandon the Iran nuclear agreement.

“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 Obama’s deal,” Darroch wrote.

Darroch announced his resignation last week after the newspaper published cables in which he’d branded the Trump administration dysfunctional and inept. The White House responded by refusing to deal with him, and Trump branded the ambassador a “pompous fool” in a Twitter fusillade.

U.K. police are hunting the culprits behind the leak — and, contentiously, have warned journalists that publishing the documents “could also constitute a criminal offence.”

Yet both Johnson and Jeremy Hunt, the two contenders to become Britain’s next prime minister, have defended the media’s right to publish.

“We have to make sure that we defend the right of journalists to publish leaks when they are in the national interest,” Hunt said.

British officials have said they have no evidence that hacking was involved in the documents’ release, and that the culprit is likely to be found among politicians or civil servants in London.

Police are investigating the leak as a potential breach of the Official Secrets Act, which bars public servants from making “damaging” disclosures of classified material. Breaking the act carries a maximum sentence of two years in prison, though prosecutions are rare.

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

The first memos criticising President Trump’s administration, which emerged a week ago, prompted a furious reaction from the US president and resulted in Sir Kim resigning from his role. Sir Kim wrote to Mr Johnson informing him Republican President Trump appeared to be abandoning the nuclear deal for “personality reasons” - because the pact had been agreed by his Democrat predecessor, Barack Obama.

Under the 2015 deal backed by the US and five other nations, Iran agreed to limit its sensitive nuclear activities in return for the lifting of crippling economic sanctions. However, President Trump said he did not think that the deal went far enough in curtailing Iran’s nuclear ambitions and reinstated US sanctions after withdrawing from it in May 2018.

In a tweet from June this year, the president also said he objected to Mr Obama having given Iran £1.8bn (£1.4bn) as part of the deal. Commentators later pointed out it was related to the settlement of an unfulfilled military order from the 1970s. Tehran recently announced it would break a limit set on uranium enrichment, in breach of the deal’s conditions. However the UK, Germany and France say they are still committed to the deal.

The British ambassador’s memo is said to have highlighted splits amongst US presidential advisers; he wrote that the White House did not have a strategy of how to proceed following withdrawal from the deal.

According to the paper, in his memo to Mr Johnson, Sir Kim wrote: “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 Obama’s deal.

“Moreover, they can’t articulate any ‘day-after’ strategy; and contacts with State Department this morning suggest no sort of plan for reaching out to partners and allies, whether in Europe or the region.”

he warning prompted a backlash from newspaper editors and MPs on Saturday, defending the freedom of the press.

The Met Police then released a second statement making clear journalists who released further details of the former ambassador’s communications could be in breach of the Official Secrets Act, in which case there is no public interest defence in law.