Andy Burnham exchanged messages with someone impersonating Donald Trump’s chief of staff, it has emerged.

The UK prime minister was in contact with an unknown individual pretending to be top White House aide Susie Wiles before concerns were raised about the incident.

No messages of significance were sent, and the suspicious activity was quickly reported to the appropriate authorities, as is understood.

The British embassy in Washington was so concerned it raised the matter with the White House, according to Playbook, which first reported the exchange.

A UK government spokesperson said: “We do not comment on national security matters.”

Last year, The Wall Street Journal reported that the FBI had launched an investigation into efforts to access Ms Wiles’ phone after an unknown person contacted prominent Republicans and business chiefs while pretending to be her.

It is unclear when the messages were sent and what was discussed between Mr Burnham, who succeeded Sir Keir Starmer in Downing Street on July 20, and the impersonator.