Britain scrambled on Monday to stem damage to its relations with Washington and find the leaker of cables in which the UK ambassador called US President Donald Trump “inept”.

The confidential telegrams from ambassador Kim Darroch created a political firestorm in London after their publication in the Mail on Sunday newspaper.

One of them called the Trump administration “uniquely disfunctional” while another characterised the US leader as “incompetent” and “insecure”.

Their release came just a month after Trump’s state visit to Britain during which he visibly enjoyed himself while dining with Queen Elizabeth II and touring Buckingham Palace with his family. They also threatened to complicate London’s efforts to strike a new trade deal with Washington that could help mitigate potential damage from Britain’s withdrawal from the European Union.

Trump fired back by saying that people in his administration were “not big fans” of London’s man in Washington.

“The ambassador has not served the UK well, I can tell you that,” Trump told reporters on Sunday. “We are not big fans of that man and he has not served the UK well. So I can understand it, and I can say things about him but I won’t bother.”

UK officials took turns defending Darroch as a professional who was carrying out his duties by providing “frank” assessments of the latest developments in the White House.

“We need to find out how it happened, not least to give confidence to our teams all over the world that they can continue to give us their frank assessments,” Foreign Secretary Jeremy Hunt said on Monday.