Boris Johnson is likely to approve the use of Huawei technology in the UK’s new 5G network against the pleas of the US government, a former national security adviser has said.

Sir Mark Lyall Grant, who was Theresa May’s national security adviser, said that the security services had repeatedly concluded over several years that they were able to mitigate any potential threats posed by the Chinese technology.

The US has warned the British government it “would be madness” to use Huawei technology and senior Washington officials have said numerous times that the Trump administration would reassess intelligence sharing with the UK in light of such a move.

However, UK security figures dispute the claim and Britain has already used some Huawei technology in previous mobile networks. A final decision is expected later this month.

Lyall Grant told the Observer: “This has been gone into now by three different administrations, and I think the outcome is quite likely to be the same – that the intelligence agencies are expressing confidence that they can sufficiently mitigate any potential security threat to allow Huawei to continue to provide at least the non-core telecommunications equipment for 5G rollout. The government has developed an oversight mechanism which they are confident will work.

“Combine that with the fact that Huawei has more advanced technology than the alternatives, I think it is relatively likely that Boris Johnson will come to the same conclusion.”

Two of Britain’s biggest telecoms companies, BT and Vodafone, are understood to be drafting a letter to Johnson, setting out their support for Huawei’s involvement in 5G.

Last night, a senior Huawei executive, Victor Zhang, said there was simply “no justification” for banning the company on cyber security grounds.

“After looking at the facts, we hope the government agrees – so that our customers can keep the UK’s 5G roll-out on track and meet the prime minister’s promise of gigabit connectivity for all,” he said.

“Giving Huawei the go-ahead to continue supplying equipment will mean telecoms companies have access to the best technology and the breadth of suppliers they need to build secure, resilient and reliable networks.”

The dispute was a sign that Britain would be repeatedly asked to take a side in disputes between the US and China, Lyall Grant added. “The interesting thing about Huawei is that it is the first, but by no means the only issue on which the risk is over the next decade, we are going to be pressured to choose,” he said. “And that is a choice that on some issues the UK government is not going to want to make.”