Huawei is the world's biggest supplier of network gear used by phone and internet companies (Picture: PA).
Allowing the Chinese tech giant Huawei to have a role in building the UK's 5G network poses an unnecessary risk to national security, a former MI6 chief has warned.
Sir Richard Dearlove said using Huawei equipment could place the Chinese government in a "potentially advantageous exploitative position" in the UK's future telecoms network.
He joins a growing chorus of senior figures voicing concern after it was reported last month that Theresa May is ready to give the green light to the firm supplying "non-core" elements of the system.
The Government has insisted no final decision has been taken on Huawei's involvement in the UK's 5G data network, although the issue remains highly sensitive in Whitehall.
Sir Richard Dearlove's comments come as US President Donald Trump signed an executive order effectively banning American firms from using foreign telecoms deemed to pose a threat to national security.
Although it does not name Huawei, it is widely considered to be aimed at the firm following repeated warnings by US officials that it could be used by the Chinese state to spy on or sabotage foreign networks.
Huawei has criticised President Trump's decision.
In a foreword to a new report by the Henry Jackson Society (HJS) think tank, Sir Richard said the involvement of Huawei had to be viewed as a "potential security risk" to the UK.
"The fact that the British Government now appears to have decided to place the development of some its most sensitive critical infrastructure in the hands of a company from the People's Republic of China (PRC) is deeply worrying," he wrote.
"The PRC uses its sophisticated technical capabilities not only to control its own population (to an extreme and growing degree), but it also conducts remotely aggressive intelligence gathering operations on a global scale.
"No part of the communist Chinese state is ultimately able to operate free of the control exercised by its Communist Party leadership.
"To place the PRC in a potentially advantageous exploitative position in the UK's future telecommunications systems therefore is a risk, however remote it may seem at the moment, we simply do not need to take."