The UK has to be “mindful” that the US has the power to impact the technology available to other countries in light of the Huawei ban, the former head of the National Cyber Security Centre (NCSC) has said.

Ciaran Martin – who left the NCSC in August – told MPs that any potential change in president was not likely to mean a different course of action for the UK, although he warned “never say never”.

The Government decided in July to ban the Chinese firm from having a role in the country’s 5G network, owing to tougher US sanctions restricting Huawei’s ability to build chips.

As a result, British telecoms firms were told to remove Huawei equipment from the 5G network by 2027 and stop purchasing new 5G equipment from it by the end of the year.

Such changes are expected to cost billions across the telecommunications industry and delay the deployment of 5G by up to three years.

Mr Martin said the possibility of Donald Trump losing his bid for a second term as US president was something the NCSC had to “grapple with” when making its recommendations on Huawei in July.

“The power of the US legal system and sanction system has been demonstrated, so under a different hypothetical, let’s say there is a change of presidents in January 2021 and then a further one in January 2025 which reinstates them, a UK system has to be mindful of the fact that the US federal government has the sort of power to impact the technology available in markets like the UK,” Mr Martin told the Commons Science and Technology Committee.

“So it’s not just a question of whether you sort of swing with the wind of change in US politics, it’s to what extent … you have to, from a risk management point of view, you have to take into account that this could happen and could happen at some point in the 2020s and 2030s.”

The former UK cybersecurity boss’s words echo what Digital Secretary Oliver Dowden has also told the committee, saying that he doubted the US would change its position on Huawei irrespective of the country’s leadership.

It comes as BT announced that it had signed a deal with Nokia, making the Finnish firm BT’s largest equipment provider, in the wake of the Huawei ban.