Explained: Chinese firm Huawei, and the leak that has claimed a UK minister’s job

The report said that Britain’s National Security Council (NSC), which is chaired by the Prime Minister, had decided the previous evening to allow Huawei to help build antennas and other “noncore” infrastructure.

May, the report said, had overruled concerns expressed at the NSC meeting by her Home Secretary Sajid Javid, Foreign Secretary Jeremy Hunt, Defence Secretary Gavin Williamson, International Trade Secretary Liam Fox, and International Development Secretary Penny Mordaunt. The publication of the report was followed by outrage in Britain’s political class. There were calls for a “full and proper leak inquiry”, which Cabinet Secretary Sir Mark Sedwill, Britain’s top civil servant, began the very next day on the orders of Prime Minister May.

Why was the leak considered serious?

The NSC, consisting of the PM and her seniormost cabinet colleagues, invites top officials from the armed forces and intelligence agencies to its weekly meetings from time to time. The Government Communications Headquarters (GCHQ), and the MI6 and MI5 agencies provide information to members of the political leadership, all of whom are sworn to secrecy.

The proceedings are entirely confidential, and the BBC reported that information from the NSC had never before been made public. Senior ministers were quoted as saying that while there were “huge concerns” over “getting into bed” with Huawei, the leak was “extraordinary” and “simply not acceptable”, given that “the security council is the holy of holies”. Lord Augustine O’Donnell, who was cabinet secretary under three Prime Ministers from 2005 to 2011, told the BBC that leaks from the NSC were “incredibly serious, a complete outrage”.

In her letter to Gavin Williamson sacking him, May said: “This is an extremely serious matter, and a deeply disappointing one. It is vital for the operation of good government and for the UK’s national interest in some of the most sensitive and important areas that the members of the NSC — from our Armed Forces, our Security and Intelligence Agencies, and the most senior level of government — are able to have frank and detailed discussions in full confidence that the advice and analysis provided is not discussed or divulged beyond that trusted environment.”

May told Williamson that she was “concerned by the manner in which [he had] engaged with [the] investigation”. All NSC attendees, she wrote to him, had “answered questions, engaged properly, provided as much information as possible to assist with the investigation, and encouraged their staff to do the same”, but his “conduct ha[d] not been of the same standard as others”. She referred to her subsequent meeting with Williamson in which she had shared with him “compelling evidence suggesting [his] responsibility for the unauthorised disclosure”, and informed him that she “no longer ha[d] full confidence in [him] as secretary of state for defence and a minister in [her] cabinet and asked [him] to leave Her Majesty’s government”.

Why are there concerns about Huawei?

Governments across the world have long been suspicious of Huawei. The United States government has banned the company from its network, and advised its allies in the Five Eyes intelligence alliance — the UK, Australia, New Zealand and Canada — to do the same. Huawei (pronounced ‘wah-way’) is a Chinese company based in Shenzhen, which was founded by Ren Zhengfei, who used to be an engineer in China’s People’s Liberation Army. It is now the world’s second largest mobile phone maker, selling more phones than Apple, and coming behind only Samsung. The US says that Huawei’s close ties with the Chinese government makes it a national security risk.