LONDON (Reuters) - British Prime Minister Theresa May fired Defence Secretary Gavin Williamson on Wednesday over the leak of information about Chinese telecoms company Huawei.

FILE PHOTO: Britain's Prime Minister Theresa May and Britain's Defence Minister Gavin Williamson arrive for a multilateral meeting of the North Atlantic Council with Georgia and Ukraine, during the NATO summit in Brussels, Belgium July 12, 2018. REUTERS/Darrin Zammit Lupi/File Photo

Below is a copy of her letter to Williamson:

Dear Gavin,

Thank you for your time this evening. We discussed the investigation into the unauthorized disclosure of information from the National Security Council meeting on 23 April.

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.

That is why I commissioned the Cabinet Secretary to establish an investigation into the unprecedented leak from the NSC meeting last week, and why I expected everyone connected to it -- Ministers and officials alike -- to comply with it fully. You undertook to do so.

I am therefore concerned by the manner in which you have engaged with this investigation. It has been conducted fairly, with the full co-operation of other NSC attendees. They have all answered questions, engaged properly, provided as much information as possible to assist with the investigation, and encouraged their staff to do the same. Your conduct has not been of the same standard as others’.

In our meeting this evening, I put to you the latest information from the investigation, which provides compelling evidence suggesting your responsibility for the unauthorized disclosure. No other, credible version of events to explain this leak has been identified.

It is vital that I have full confidence in the members of my Cabinet and of the National Security Council. The gravity of this issue alone, and its ramifications for the operation of the NSC and the UK’s national interest, warrants the serious steps we have taken, and an equally serious response.

It is therefore with great sadness that I have concluded that I can no longer have full confidence in you as Secretary’ of State for Defence and a Minister in my Cabinet and asked you to leave Her Majesty’s Government. As you do so, I would like to thank you for the wider contribution you have made to it over the last three years, and for your unquestionable personal commitment to the men and women of our Armed Forces.