Theresa May has been accused of “nesting a dragon” at the heart of the UK’s communications systems following reports she is prepared to allow Chinese tech giant Huawei to help build the country’s 5G network.

Huawei has been accused of being a security risk as it is too closely controlled by the Chinese government – something it denies.

Tory MP Tom Tugendhat, the chair of the Commons foreign affairs committee, accused the prime minister on Wednesday of putting the UK’s intelligence relationship with the US at risk.

A Whitehall leak inquiry is under way after details emerged of a National Security Council meeting at which May was said to have given the green light to Huawei being involved in the “non-core” elements of the 5G network.

Speaking during PMQs, May said the government was “committed to taking decisions supported by a hard-headed, technically informed assessment of the risk”.

But Tugendhat said the decision was “frankly extraordinary” given the warnings from both the US and Australia that Huawei should not be granted contracts.

“Could the prime minister explain why she feels ignoring two of our closet intelligence allies and putting in danger a 70-year intelligence sharing relationship that underpinned security of UK is worth it for Chinese commercial gain?” he asked.

“The decision that has been discussed in many parts of the world at the moment is the possibility we will be be nesting a dragon in the critical national infrastructure of the UK.”

The US has warned that there is no safe level of involvement by Huawei in the 5G networks branded it an “unacceptable risk” to the West.

Robert Strayer, the deputy assistant secretary for cyber at the State Department, said earlier this week US would have to reassess its intelligence-sharing arrangements.