Gavin Williamson has been sacked as defence secretary following an inquiry into a leak from a top-level National Security Council meeting.
Downing Street said the PM had “lost confidence in his ability to serve” and Penny Mordaunt will take on the role.
The inquiry followed reports over a plan to allow Huawei limited access to help build the UK’s new 5G network.
Mr. Williamson, who has been defence secretary since 2017, “strenuously” denies leaking the information.
In a meeting with Mr. Williamson on Wednesday evening, Theresa May told him she had information that provided “compelling evidence” that he was responsible for the unauthorised disclosure.
In a letter confirming his dismissal, she said: “No other, credible version of events to explain this leak has been identified.”
Responding in a letter to the PM, Mr. Williamson said he was “confident” that a “thorough and formal inquiry” would have “vindicated” his position.
“I appreciate you offering me the option to resign, but to resign would have been to accept that I, my civil servants, my military advisers or my staff were responsible: this was not the case,” he said.
The inquiry into the National Security Council leak began after the Daily Telegraph reported on the Huawei decision and subsequent warnings within cabinet about possible risks to national security over a deal with Huawei.
