The government may be close to announcing a U-turn on its controversial decision to allow Huawei to supply 5G technology, the culture secretary has hinted by saying US sanctions appear likely to affect the Chinese company. Oliver Dowden told members of a special defence select committee scrutinising Huawei that an emergency review ordered last month was close to running its course and that a change in policy would probably be necessary. “Given that those sanctions are targeted at 5G and [are] extensive, it is likely to have an impact on the viability of Huawei as a provider for the 5G network,” the cabinet minister told MPs on Tuesday. The work is being undertaken by the National Cyber Security Centre, an arm of GCHQ, which was asked in May by Downing Street to examine the effect of a proposed ban on supplying US semiconductors and software to Huawei. Dowden said the NCSC was “pretty much finished” in terms of determining the technical impact, and that he and the specialists “were going through the final stages of it” to determine the policy response. Whitehall sources have indicated that a particular concern is that Huawei would become reliant on unfamiliar and untested components, which could be exploited for mass or targeted surveillance by Beijing and others. In January, on the advice of the UK’s intelligence agencies, Boris Johnson concluded that it would be safe to deploy Huawei in future 5G networks, as long as the Chinese company was declared a “high-risk vendor” and therefore subject to a 35% cap on its share of the market. That decision has been criticised by Donald Trump’s administration and a growing group of rebel Conservatives, which want Huawei eliminated from 5G in the UK in two to three years. They argue a Chinese company poses an unacceptable long-term security risk to western phone networks. Rebel Conservatives believe they have enough votes to overturn Johnson’s 80-seat majority whenever the new 5G rules are put to the vote in a fresh bill, but they are hoping Downing Street will capitulate before then. One rebel who sits on the defence committee, the backbencher Mark Francois, said: “Are you really telling us that there’s still a possibility we will allow a company effectively owned by the Chinese Communist party to have a meaningful role in our telecommunications network?” Francois repeatedly pressed Dowden on whether the UK government believed that high-risk vendors such as Huawei should be removed in future. The minister agreed but added the government had “not set out a timetable” for doing so, which is a key demand of the rebels. A bill to legislate for 5G supply rules is due to be introduced before the summer recess in July, but Dowden conceded that if the Huawei policy changed as a result of the review, he would have to “ask parliament’s forbearance” and seek “a slight delay”, suggesting draft laws might not emerge until September. After the committee hearing, Victor Zhang, a vice-president of Huawei, said the company remained committed to the UK. “We are investing billions to make the prime minister’s vision of a ‘connected kingdom’ a reality, so that British families and businesses have access to fast, reliable mobile and broadband networks wherever they live.”