Andy Burnham exchanged messages with somebody impersonating one of US president Donald Trump’s closest advisers in an embarrassing security breach for the UK prime minister’s team.

Downing Street declined to comment “on national security matters”, but has not denied that Burnham was in communication with someone claiming to be White House chief of staff Susie Wiles.

People briefed on the matter insisted that the conversations were by message – not a phone call – and that no significant information was conveyed in the messages.

They said concerns were raised about the exchanges and that the suspicious activity was “quickly reported to the appropriate authorities” after a few messages between the two parties.

RM Block

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Burnham has yet to meet Trump in person since taking office last month. The two have spoken on the phone, and the US president has heavily criticised the UK’s policies on fossil fuels and immigration.

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Politico, which first reported the security breach, said the British embassy was so concerned about the incident that it reported it to the White House, which declined to comment.

Last year the FBI investigated an attempt to hack the personal phone of Wiles after politicians and US business executives received texts and phone calls from someone claiming to be the chief of staff.

“The White House takes the cyber security of all staff very seriously, and this matter continues to be investigated,” a White House spokesperson said at the time.

It is not the first time a senior British politician has been exposed to a security breach by someone claiming to be a senior foreign political figure.

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In 2024, David Cameron, then the foreign secretary, was the victim of a hoax call from someone pretending to be former Ukrainian president Petro Poroshenko.

A number of text messages were also exchanged between the impersonator and Cameron, who regretted his mistake, according to a foreign office spokesperson at the time.

“Whilst the video call clearly appeared to be with Mr Poroshenko, following the conversation the foreign secretary became suspicious,” the spokesperson said. – Copyright The Financial Times Limited 2026