Boris Johnson under mounting pressure over looming Huawei decision

The United States warned that British sovereignty would be put at risk by allowing the firm to play a role in the 5G network.

US secretary of state Mike Pompeo described the decision facing the National Security Council as “momentous” in a last-ditch plea to ministers who are expected to make the call on Tuesday.

The Financial Times reported the meeting is expected to agree the company can play a restricted role, with ministers looking to impose a cap on its market share to prevent over-reliance on its equipment.

The US administration has previously warned allies not to allow Huawei to form part of their 5G networks, claiming it would be a security risk, something the company vehemently denies.

But Mr Pompeo wrote on Twitter on Sunday night: “The UK has a momentous decision ahead on 5G.

“British MP Tom Tugendhat gets it right: ‘The truth is that only nations able to protect their data will be sovereign’.”

He retweeted a comment by Mr Tugendhat, the chairman of the Commons Foreign Affairs Committee in the last parliament, in which the MP said: “Sovereignty means control of data as much as land.

“We need to decide what we’re willing to invest in and who we’re willing to share our tech with.

“The real costs will come later if we get this wrong and allow Huawei to run 5G.”

Mr Tugendhat has been granted permission to ask an urgent question about the situation in the Commons on Monday afternoon.

Washington’s ambassador to the UK, Woody Johnson, said Mr Tugendhat’s point was “undeniable”, adding that “doing 5G right goes beyond data ‘mitigation’ – it’s about national sovereignty”.

Mr Pompeo is due to meet the Prime Minister and Foreign Secretary Dominic Raab on a visit to London this week.

Senior Tories – including former Cabinet ministers – also voiced concerns about the imminent decision.

Former defence secretary Penny Mordaunt said ministers must decide: “What are the standards, values and reliability we want from any company our national infrastructure depends upon?”

But she acknowledged that the decision must also weigh up what the alternative would be if the UK rejected Huawei’s involvement.

On the issue of security, she told the PA news agency: “I don’t think anyone doubts that there are concerns, what is in question is whether they should be offset against other issues.

“And that is about more than the technical ability to limit the scope of their involvement. It is also about values and trust.”

Former Brexit secretary David Davis warned the UK was on the cusp of an “almost irreversible” decision.

He said that although the US had “sometimes been heavy handed in their dealings with the Chinese” they “have a point” about Huawei.

He claimed potential vulnerabilities could be exploited by the Chinese later down the line.

He told PA: “The problem with this is that it is irreversible. Once you have done it, the technology is not designed to be ‘plug and play’ – where you can pull out a Huawei unit and put in a Samsung one – it’s effectively proprietary, a bit like having an Apple plug.

“So it’s quite close to an irreversible mistake, and it’s also close to a mistake you wouldn’t know if you’d made it.”

Former foreign secretary Jeremy Hunt warned against a “dependency” on a Chinese company in delivering 5G technology.

He told BBC Radio 4’s Today programme: “I must admit I always wondered whether it was wise to allow ourselves to become technologically dependent on another country, whichever country, for something as critical as 5G technology.”

Justice Secretary Robert Buckland said the calculation would be taken in terms of the UK’s national interest.

“The decision we make will be based upon our own sovereign right to choose. It’s Britain that will have to live with the consequences of that,” he told BBC Radio 4’s Westminster Hour following Mr Pompeo’s intervention.

“There are risks but we will make an informed decision based on the evidence and we will do so in an autonomous way.”

Professor Malcolm Chalmers, the deputy director of defence and security think tank the Royal United Services Institute, said he did not believe the US would cut off intelligence-sharing if Huawei was given a role in the UK’s 5G network.

“When the dust settles, I find it very hard to believe that the US would want to cut off its access to UK-generated intelligence as a response to a decision of this nature. I don’t take that threat very seriously,” he said.

Last year, the US imposed trade restrictions on Huawei over concerns about the company’s security and ties to the Chinese government.

Allegations that its telecommunications equipment could be used to spy on people have been repeatedly denied by the firm.