British Defence Secretary, Gavin Williamson has been sacked 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, continues to deny 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.”