The UK is poised to end the use of Huawei technology in its 5G network as soon as this year over security concerns.
Boris Johnson is set for a major policy change after GCHQ is believed to have reassessed the risks posed by the Chinese company.
The prime minister decided in January to allow Huawei to play a limited role in the UK's 5G network as he defied security concerns, particularly from the US, about the firm.
But a study set to be presented to Mr Johnson this week will declare that US sanctions on Huawei will force the company to use technology that is "untrusted", reports say.
The news was first reported in the Sunday Telegraph and Sunday Times newspapers - a security source confirmed to Sky News that the reports are "broadly accurate".
Officials are said to be crafting proposals to prevent new Huawei equipment being installed in the 5G network in as little as six months.
Asked about the reports on Sky News' Sophy Ridge On Sunday show, Health Secretary Matt Hancock said he wouldn't comment on "leaks".
But he added: "What I can say though is when we came out with an interim report on this earlier in the year, there were a number of conditions that needed to be met.
"So I'm sure that the National Security Council will look at those conditions and make the right decision on this to make sure that we have both a very strong telecoms infrastructure and everyone can get a phone signal.
"But also that it is secure and that the British government can have confidence that it is secure."
In response to the reports, Huawei's head of international media, Paul Harrison, claimed that UK policy is "being dictated" by US President Donald Trump's administration.
In a series of tweets, Mr Harrison claimed that the US was "fighting to claw back market position" on 5G from "global leader" Huawei.
He added the US had "consistently failed to provide evidence to back up endless spurious allegations".
"Shouldn't the US respect a United Kingdom in the post-Brexit era being in a position to chose its own telecommunication strategy?," Mr Harrison asked.
In January, Mr Johnson gave Huawei the green light to build 35% of Britain's next generation of internet infrastructure, with other conditions that it will be excluded from all safety critical networks and from sensitive geographic locations such as nuclear sites and military bases.
The involvement of the Chinese tech firm in Britain's 5G network is believed to have caused tension between the US and UK in recent months.
A report by GCHQ's National Cyber Security Centre has decided the US sanctions barring Huawei from using technology relying on American intellectual property has had a "severe" impact on the firm.
A number of prominent figures on the Conservative backbenches have also raised concerns.
Critics fear that allowing Huawei to build the network would be handing control of infrastructure to Beijing.
There are also concerns that, with the company's close links to the Chinese government, the equipment could be used for espionage, something the company has always denied.
Conservative MP Tobias Ellwood, the chair of the House of Commons defence committee, told Sky News: "It's very wise of the government to take a stock check as to where we are and who we can trust in the world.
"This is a technical decision; it's about whether we can trust Huawei or indeed other high-risk vendors in the UK.
"But it's also whether, politically, we want to be joining forces with a country that we see perhaps in a very different light after COVID-19, given what they've done in trying to suppress the outbreak originally.
"And what they're doing in Hong Kong, the debt-trap diplomacy that we see around the world with countries getting into financial debt with them, their military actions in the South China Sea.
"Some big questions about China, but ultimately it's also about our own telecoms security."
Former MI6 boss Sir John Sawers, writing in the Financial Times, said: "The last six months have revealed more about China under President Xi Jinping than the previous six years.
"China is overplaying its hand and giving western leaders no option but to stand up to it."
Backing a u-turn on giving Huawei a role in the UK's 5G infrastructure, Sir John pointed to fresh US sanctions as meaning there are "now sound technical reasons for the UK to change January's decision".
Victor Zhang, Huawei's vice-president, said: "We are working closely with our customers to find ways of managing the proposed US restrictions so the UK can maintain its current lead in 5G.
"As ever, we remain open to discussions with the government.
"We believe it is too early to determine the impact of the proposed restrictions, which are not about security, but about market position.
"All our world-leading products and solutions use technology and components over which the UK government has strict oversight.
"Our technology is already extensively used in 5G networks across the country and has helped connect people throughout lockdown."
Swedish telecoms company Ericsson has said it would be capable of replacing all of the Huawei equipment in the UK's 5G network if the British government decides to ban the Chinese company.
In an interview with Sky News last week, the company's president for Europe, Arun Bansal, said Ericsson was not lobbying for its Chinese rival to be banned - but would be capable of meeting the demand if it was.
"Ericsson is not described as a high-risk vendor," Mr Bansal told Sky News.