A criminal investigation into the leaking of secret discussions of the National Security Council has not been ruled out, a Cabinet minister has told MPs.

The Government is facing demands for an official inquiry over reports that the involvement of Chinese tech giant Huawei in the UK’s new 5G network was approved at this week’s NSC in the face of opposition from some ministers.

Prime Minister Theresa May signalled her anger at the unprecedented breach in the secrecy which normally surrounds a forum where the most senior Government ministers are briefed by heads of security and intelligence agencies MI5, MI6 and GCHQ.

Mrs May’s official spokesman declined to say whether a leak inquiry had been launched, but told reporters: “The Prime Minister is clear that the protection of information on matters of national security is of the highest importance.”

And Culture Secretary Jeremy Wright told the House of Commons: “We cannot exclude the possibility of a criminal investigation.”

Jeremy Wright
Jeremy Wright told MPs a criminal investigation had not been ruled out (House of Commons/PA)

Labour is demanding a full investigation into the leak, which has reportedly caused concern within the secret services.

In an urgent question to the House of Commons, shadow Cabinet Office minister Jo Platt said: “If a minister did leak the information, they are not fit to serve in the Cabinet – and are certainly not fit to be prime minister.

“Indeed, if the leak was for an advantage in a Tory leadership race that would be truly shocking.

“Critical issues of national security should be handled with utmost care, not used as political ammunition in a Tory party civil war.

“A full leak inquiry should be undertaken and, if identified, the individual should immediately resign or be removed from their position.”

Mr Wright said it was essential the intelligence agencies had confidence that advice given to ministers would remain private.

“If they do not feel that, they will not give us that advice and Government will be worse as a result,” he said.

Calls for a inquiry were backed by former national security adviser Lord Ricketts, who told the BBC it was the first major leak from the NSC since its inception in 2010.

He suggested investigators from the Security Service, MI5, could be brought in “to make the culprit feel very uncomfortable”.

Dominic Grieve
Intelligence and Security Committee chairman Dominic Grieve said the leak was ‘deeply worrying’ (Kirsty O’Connor/PA)

Dominic Grieve, the chairman of the Parliamentary Intelligence and Security Committee, said the leak was “deeply worrying”.

“The principle that what is discussed at the NSC is kept totally confidential is really important,” he told the BBC.

“If it turned out that it was a member of the Cabinet – or indeed a minster who was attending the NSC – they should be sacked immediately.”

Mr Wright repeated the Government’s position that no final decision has been made on whether Huawei should be allowed to bid for contracts in the hi-tech communications project.

Reports suggest it could be given work on “non-core” elements of the 5G network, despite misgivings apparently voiced at the NSC meeting by ministers including Jeremy Hunt, Sajid Javid, Gavin Williamson and Penny Mordaunt.

The US has barred Huawei from involvement in official networks and put pressure on its Five Eyes intelligence partners to do the same, over security concerns surrounding the company’s links with the Chinese government.