The UK government has approved the participation of Huawei in some “non-core” parts of Britain’s 5G data network. However, it has banned the Chinese firm from participating in sensitive “core” parts of the project.

As reported by the Daily Telegraph, the decision to permit Huawei capped access to the development of the UK’s 5G network, was taken even though there were warnings about the security risks from senior ministers.

However, some close to the meeting say the decision was signed off unanimously and that security worries were echoed by the move to heavily restrict Huawei’s involvement.

The approval was only granted by Theresa May on the understanding that the Chinese tech giant would face severe restrictions, the source said.

According to sources compiled by Forbes, the CIA has warned top British officials that “the Chinese ministry of state security -its principle security and espionage organization- had approved government funding for Huawei.”

The sources claim that “Only the most senior UK officials are believed to have seen the intelligence, which the CIA awarded a strong but not cast-iron classification of certainty.”

Tom Tugendhat, chairman of the Commons foreign affairs committee, tweeted that allowing Huawei to build some of the UK’s 5G infrastructure would “cause allies to doubt our ability to keep data secure and erode the trust essential to #FiveEyes co-operation”. He went on to say: “There’s a reason others have said no.”

Huawei has insisted repeatedly that it is not controlled by the Chinese government or refuted any notion that its devices could be used for espionage purposes.