Gavin Williamson has been sacked as guard secretary following an investigation into a break from a top-level National Security Council meeting.
Bringing down Street said the PM had “lost trust in his capacity to serve” and Penny Mordaunt will take on the job.
The request pursued reports over an arrangement to permit Huawei constrained access to help manufacture the UK’s new 5G organize.
Mr Williamson, who has been barrier secretary since 2017, “strenuously” denies releasing the data.
In a gathering with Mr Williamson on Wednesday evening, Theresa May revealed to him she had data that given “convincing proof” that he was in charge of the unapproved revelation.
In a letter affirming his expulsion, she stated: “No other, tenable variant of occasions to clarify this break has been distinguished.”
Reacting in a letter to the PM, Mr Williamson said he was “sure” that an “intensive and formal request” would have “vindicated” his position.
“I value you offering me the choice to leave, yet to leave would have been to acknowledge that I, my government employees, my military counsels or my staff were capable: this was not the situation,” he said.