Mike Pompeo, the US secretary of state, has ramped up the pressure over the use of Huawei technology in 5G networks hours before Donald Trump was expected to demand that the UK rethinks its plan to do business with the Chinese company.

The US president is due to meet Theresa May in Downing Street on Tuesday. There is growing speculation that her successor as prime minister could overturn her decision on Huawei.

Asked about the issue on a trip to the Netherlands, Pompeo said he was urging “our allies and our partners and our friends, don’t do anything that would endanger our shared security interests or restrict our ability to share sensitive information.”

May decided at a fraught meeting of the UK’s national security council in April that Huawei could be allowed to supply non-core 5G kit. The US has argued that relying on Chinese technology is a long-term security risk.

Over the weekend several Conservative leadership candidates – including Sajid Javid, the home secretary, and Jeremy Hunt, the foreign secretary – sought to portray themselves as concerned about the future use of Huawei technology.

That, coupled with the US pressure, has led some Conservatives to believe the Huawei proposal will be reversed after the party chooses a new leader and prime minister this summer.

Bob Seely, the Isle of Wight MP, said: “This should be a no-brainer – all the leadership candidates should be saying they should prioritise our alliance with the US.”

British officials indicated on Monday that no final decision on Huawei would be made this week, despite pressure from the US for a rapid change of heart, implying that a final announcement will require the stamp of a new prime minister and cabinet.

Boris Johnson, the frontrunner in the leadership race, declined to say whether he would rethink May’s Huawei policy, despite previous indications that he wanted to move closer to the US on the technology issue.

Another serious contender, Michael Gove, has yet to publicly discuss the topic, giving insiders at Huawei hope that they will be allowed to continue supplying telecoms equipment to BT, Vodafone and O2.

British civil servants stressed that the UK had a unique architecture in its telecoms network, and the country could not simply take a decision to try to exclude itself from the long-term growth in Chinese economic influence.

They added that the chief priorities were protection of the UK-US intelligence relationship as well as a diversification of choice among network technology providers and and an increase in telecoms standards.

Other former Whitehall insiders said the next prime minister would have leverage to resist the US warnings. The US is reliant on UK signals intelligence for the targeting of missions in Syria and Iraq. The belief of British officials is that the Trump administration argument against Huawei is essentially economic, part of a growing battle over trade between the world’s largest economy and China.

It is understood that the decision to allow Huawei to supply some 5G technology was made by May in line with advice from UK intelligence agencies, who argued that any risk that its technology could be used for surveillance by the Chinese government could be dealt with.

A special unit known as the Cell evaluates Huawei software on behalf of GCHQ. No evidence of secret backdoors has been discovered, although concerns about the quality of the Chinese company’s coding have been raised in the past.

At the weekend Javid said that he would not want any company “that has a high degree of control by a foreign government to have access to our very sensitive telecommunications network”.

Hunt said the UK did not want to jeopardise intelligence sharing with the US. “We have to look at the technical issues which are around whether buying products from a specific country could be a backdoor to espionage, and we are looking at those very carefully,” he said.