Gavin Williamson's sacking as Defence Secretary follows days of searching for the person who leaked information from the UK's National Security Council.
Theresa May's decision to sack him could just be the start of a fresh political scandal, with calls for a police investigation mounting among MPs.
Here is how the leak developed into a major Government inquiry:
April 23 - The UK's National Security Council (NSC), the country's top security body where Cabinet minister meet, is held.
April 24 - The Daily Telegraph publishes reports that the Prime Minister agreed to allow Chinese telecoms firm Huawei to build 5G in Britain, despite security concerns raised by Cabinet ministers at the meeting.
Labour demands an official investigation into the leak from the highly secretive council.
April 25 - Dominic Grieve, chairman of the Parliamentary Intelligence and Security Committee, described leak as "deeply worrying".
Home Secretary Sajid Javid said it is "completely unacceptable" for any minister to release sensitive information and said it should "absolutely be looked at".
Gavin Williamson and Foreign Secretary Jeremy Hunt publicly deny they are responsible.
In a statement, Mr Williamson says neither he nor any of his team had “divulged information from the National Security Council”.
April 26 – An ultimatum is reportedly issued to ministers over the leak of the secret discussions.
Reports emerge that Cabinet Secretary Sir Mark Sedwill has demanded ministers in attendance at the NSC meeting confess or deny if they were behind the leak.
Downing Street refuses to say whether an inquiry is under way, despite calls for police to become involved.
Sources close to International Trade Secretary Liam Fox and International Development Secretary Penny Mordaunt also deny they were involved.
April 27 – It is reported that members of the Cabinet are expected to be summoned for interviews as part of a formal inquiry headed by Sir Mark Sedwill.
Ministers and aides are reportedly issued questionnaires requiring them to explain where they were in the hours following the NSC meeting.
China’s ambassador to the UK, Liu Xiaoming, defends the tech giant Huawei and urges the Government to act independently and resist external pressure.
April 28 – Jeremy Hunt says he has been questioned by officials as part of a leak probe and is prepared to hand over his phone.
He says the UK should exercise “a degree of caution” about the role of large Chinese firms such as Huawei.
April 29 – The US delivers a warning that there is no safe level of involvement by Chinese tech giant Huawei in the 5G networks of Western powers.
May 1 – Gavin Williamson is sacked as Defence Secretary following an inquiry into the leak of information.
Downing Street said Theresa May asked Mr Williamson to leave the Government having “lost confidence in his ability to serve”.Williamson denies his involvement again, posting his reply letter to the Prime Minister on Twitter.
Deputy Labour leader Tom Watson calls for their to be a police investigation, citing the Official Secrets Act.
May 2 - Amber Rudd said it is up to the Prime Minister as to whether a criminal investigation into the leak should go ahead.