A group of high-ranking Conservative Tory MPs have reportedly expressed concern over the government's controversial move to allow Chinese technology giant Huawei to play a role in the UK's 5G network.
The letter is from four former cabinet members, including ex-Tory leader Sir Iain Duncan Smith, the BBC said.
As Vice President Mike Pence said, Prime Minister Boris Johnson's decision to give Huawei a limited role in the rollout of 5G could jeopardize a post-Brexit trade deal between Britain and America.
The letter from, among others, Sir Iain, Owen Paterson, David Davis and Damian Green states that some MPCs are "working to find a better solution to the 5G problem," according to the BBC.
The Senior Tories want providers with high risk to be excluded immediately or to run out of time.
The letter said: “We want to ensure that only trusted providers are included as prime contractors in our critical national infrastructure.
"Trustworthy providers would be companies from countries with fair market competition, the rule of law, respect for human rights, data protection and authorities without coercive measures."
When asked whether the Huawei decision could be a deal breaker in the Brexit trade talks, Pence told CNBC: "We'll see. We'll see if it is."
Regarding the UK move to allow Huawei to participate in the 5G rollout to a limited extent, Pence said: "We are deeply disappointed because when I went in the direction of the President in September I met Prime Minister Johnson and told him which one Great Britain has left Brexit. We were ready to negotiate a free trade agreement with the UK.
"However, we do not believe that the use of Huawei's assets and technology is compatible with the security or privacy concerns of the United Kingdom and the United States, and that this remains a real problem between our two countries."
The statements came after it was reported that US President Donald Trump had blown up the Prime Minister with "apoplectic" anger during a violent phone call over the 5G move.