Culture secretary Jeremy Wright warned MPs that police may become involved after details of National Security Council (NSC) discussions on the involvement of technology giant Huawei in delivery of the UK’s 5G mobile data network were leaked to a newspaper.
The warning came as it was last night reported a formal Government inquiry will be held and led by Cabinet secretary Sir Mark Sedwill.
Sir Mark, the national security adviser, wrote to ministers on the NSC yesterday reminding them of their legal responsibilities under the official secrets act.
Downing Street refused to confirm the probe, but insisted the Prime Minister regarded the protection of information concerning national security as a “matter of the highest importance”.
Amid claims by opposition parties the leak is part of plotting by rival camps in an imminent Conservative Party leadership contest, two Cabinet ministers – defence secretary Gavin Williamson and foreign secretary Jeremy Hunt – publicly denied they were responsible.
Mr Hunt said: “I think it is utterly appalling that that should happen. I have never leaked confidential Cabinet discussions and I never will.”
The Daily Telegraph reported that at a meeting of the NSC, Mrs May dismissed objections of key ministers to give the green light for Huawei to participate in the UK’s 5G communications network.
Five ministers – Mr Hunt, Mr Williamson, home secretary Sajid Javid, international development secretary Penny Mordaunt and international trade secretary Liam Fox – were reported as having expressed concern.
The United States has led calls for western allies to block Huawei from critical infrastructure over fears the company could provide sensitive information to Beijing.
SNP MP Martin Docherty-Hughes called for a “full and thorough inquiry” into the leak. “It cannot be the case that sensitive information and matters of national security are being used by Tory candidates to put their career ahead of the interests of the country,” he said.
Labour also demanded an inquiry, with shadow Cabinet Office minister Jo Platt saying any minister responsible was “not fit to serve in the Cabinet and they are certainly not fit to be Prime Minister”.
Former defence secretary Sir Michael Fallon said a Whitehall leak inquiry by civil servants was insufficient and that only a proper Scotland Yard investigation could get to the truth.
“Ministers are subject to the Official Secrets Act just like anybody else,” he said. “It is an offence to divulge secret information from the most secret of all government bodies, which is the National Security Council.
“It is extraordinary to think that a minister can leak details of the National Security Council and then think they can get away with it.”
Mr Wright told MPs a criminal investigation had not been ruled out, saying 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.
Separately, the SNP announced that its Westminster leader, Ian Blackford, is standing down from his role on the parliamentary Intelligence and Security Committee, which reviews the activities of the UK’s security services.
He will be replaced by Dundee East MP Stewart Hosie. The SNP said the change was made to better distribute responsibilities among its Westminster team.