Theresa May has given the go-ahead to Chinese telecoms giant Huawei to help build Britain’s new 5G network despite warnings of the potential threat to national security, it has been reported.

The National Security Council (NSC), chaired by the Prime Minister, agreed on Tuesday to allow the firm limited access to build “non-core” infrastructure such as antennas, according to the Daily Telegraph.

Ministers including Home Secretary Sajid Javid, Foreign Secretary Jeremy Hunt, Defence Secretary Gavin Williamson, International Trade Secretary Liam Fox and International Development Secretary Penny Mordaunt were said to have raised concerns about the decision, according to the Telegraph.

Jeremy Hunt and Sajid Javid
Jeremy Hunt and Sajid Javid are among the ministers reported to have raised concerns (Stefan Rousseau/PA)

Downing Street refused to comment on the report. A spokeswoman said: “We don’t comment on NSC discussions.”

The decision came after a number of senior security figures warned publicly of the risks entailed in allowing a Chinese firm access to the UK’s critical communications network.

MI6 chief Alex Younger has said Britain needs to decide how “comfortable” it is in allowing Chinese firms to become involved, while the head of GCHQ, Jeremy Fleming, has spoken of both “opportunities and threats” which they present.

Alex Younger
Alex Younger (Andrew Milligan/PA)

Some critics have expressed concerns that the Chinese government could require the firm to install technological “back doors” to enable it spy on or disable Britain’s communications network.

Last month a Government-led committee set up to vet Huawei’s products said it had found “significant technological issues” with its engineering processes leading to new risks to the UK network.

The decision is likely to lead to fresh strains with the US, which has banned Huawei from its government networks and urged the other nations in the Five Eyes intelligence alliance – the UK, Australia, New Zealand and Canada – to do the same.

This was taken up by Foreign Affairs Committee chairman Tom Tugendhat who tweeted: “Allowing Huawei into the UK’s 5G infrastructure would cause allies to doubt our ability to keep data secure and erode the trust essential to #FiveEyes cooperation.

“There’s a reason others have said no.”

Huawei has denied having ties to the Chinese government, but critics question how independent any large Chinese company can be, with a legal obligation on firms to co-operate with the state’s intelligence agencies.

A Department for Digital, Culture, Media and Sport spokeswoman said the security and resilience of the UK’s telecoms networks is of “paramount importance”.

“As part of our plans to provide world class digital connectivity, including 5G, we have conducted a review of the supply chain to ensure a diverse and secure supply base, now and into the future,” the spokeswoman said.

“This is a thorough review into a complex area and will report with its conclusions in due course.”