The controversial decision, taken on Tuesday at the National Security Council, comes as Philip Hammond, chancellor, prepares to travel to China to promote Britain’s participation in Beijing’s Belt and Road Initiative.
The decision to give Huawei limited access to the development of Britain’s 5G network, first reported in the Daily Telegraph, was taken despite the concerns of some ministers, including Gavin Williamson, defence secretary, over the impact on the UK’s relationship with Washington.
In February, Mike Pompeo, the US secretary of state, warned: “If a country adopts this [Huawei] and puts it in some of their critical information systems, we won’t be able to share information with them, we won’t be able to work alongside them.”
“In some cases there’s risk — we won’t even be able to co-locate American resources, an American embassy, an American military outpost.” US officials have lobbied their British counterparts against approving Huawei as a supplier.
The UK is part of the Five Eyes security alliance alongside the US, Canada, Australia and New Zealand. But while Australia and New Zealand have agreed to block or restrict Huawei, the UK has been more equivocal.
Those close to the NSC meeting say the decision was signed off collectively and that security concerns were reflected in the restrictions limiting Huawei’s involvement to non-core parts of the 5G project.
The core infrastructure is where sensitive information such as billing and customer details are stored. The non-core elements are the aerials and base stations on masts and rooftops and transmission equipment, which telecoms companies argue are passive in that data merely passes through and cannot be compromised.