The government has received a report into Huawei that is likely to change its policy over the Chinese firm’s role in the UK’s telecoms networks.
Digital Secretary Oliver Dowden said GCHQ’s National Cyber Security Centre had delivered its findings, and officials were now examining them before advising the prime minister.
NCSC is believed to have said it can no longer assure the security of Huawei’s products because of new US sanctions.
Huawei said it was open to discussions.
But one of the company’s spokesmen took a tougher line over the weekend, following newspaper reports that the government might ban the purchase of new Huawei 5G equipment by the end of the year.
“UK policy is being dictated by [the] Trump administration… shouldn’t the US respect a United Kingdom in the post-Brexit era being in a position to chose its own telecommunication strategy?” tweeted Paul Harrison, Huawei’s head of international media, UK.
Huawei’s role in the UK seemed to have been settled in January, when the government placed a cap on its market share in mobile and full-fibre fixed-line broadband networks, and excluded its involvement in the most sensitive parts of 5G known as the “core”‘.
However, the US subsequently announced fresh sanctions that forbid the Chinese firm and the third parties that make its chips from using “US technology and software to design and manufacture” its products.
Washington claims Huawei is backed by the Chinese military and poses a national security risk, claims the company denies.
NCSC has examined the impact of the sanctions, including the fact that they effectively prevent the company from being able to use critical software to design and simulate chips before their fabrication, as well as stopping third-party manufacturers from being able to use equipment needed to produce some of Huawei’s most advanced processors.
The risk is that as a consequence Huawei would have to start sourcing chips from elsewhere, which UK security officials might not be able to properly vet.
“The point of commissioning this advice from NCSC was to understand the implications of the US sanctions,” Mr Dowden told BBC Radio 4’s Today programme.
“Clearly the US sanctions will present challenges and that is what that advice is about.”
The minister suggested a final decision had yet to be taken.
But he added: “We want to diversify away from these so called high-risk vendors, of which Huawei is is the principal one… we want to be in a position where we don’t have high-risk vendors in our networks at all.”
Once the Department for Digital, Culture, Media and Sport delivers its conclusions to Prime Minister Boris Johnson, he will bring the matter before the National Security Council.
A decision is not expected to be made public before next week.
But on Thursday, MPs will discuss the issue at the House of Commons science and technology committee when it questions Huawei, Vodafone and BT about the implications of a potential ban.