Major telecoms operators are urging the Government to clarify the UK's position on Chinese giant Huawei, claiming that uncertainty could harm Britain's chances of being a world leader in 5G.
In a draft letter addressed to Cabinet Secretary Mark Sedwill, and seen by the BBC, telecoms leaders have requested a meeting with politicians to discuss their concerns following a US ban on the company.
The ban last month effectively bars US firms from selling to the company without government approval.
The action was part of the broader trade dispute between China and the US, which has accused Chinese technology companies such as Huawei of stealing trade secrets and threatening cybersecurity - possibly at the behest of the ruling Communist Party.
Chinese authorities say the United States is exaggerating security concerns to block a potential competitor.
Huawei has denied it would share user secrets with the Chinese government and demanded that the US provide evidence to show that such a risk exists. Earlier, it insisted that the trade friction with Washington was not taking much of a toll on its global business.
But US officials have made it their mission to persuade other governments to avoid working with Huawei, warning that Washington might not share sensitive information with allies if they are using Huawei equipment and networks that the Washington suspects could be compromised.
In the UK, telecoms companies have been under increased pressure to decide whether Huawei will be a part of planned 5G network rollouts planned for this year.
Vodafone will turn on its 5G service in the UK in July, and plans to use equipment supplied by the Chinese telecoms giant. EE used Huawei's equipment in its rollout last month.
A BT spokesperson said: “We are in regular contact with UK Government around this topic, and continue to discuss the impact of possible regulation on UK telecoms networks.”
In an evidence session before the Science and Technology committee on Monday, MPs compared Huawei to a company that produced gas for Nazi death camps in a tense exchange over the company's links to the Chinese government and alleged human rights abuses.
Cabinet declined to comment on the draft document. A spokesperson said: "We would ask for any decision regarding the future use of Huawei equipment in the UK not to be rushed but based on all the facts."
The Government has maintained that no decision has yet been made over Huawei's presence in 5G networks and is still carrying out a review despite calls from the US to sever ties over allegations of espionage.
Huawei's chief strategist said Tuesday the company would have become the world's number one smartphone maker by the year's end if not for "unexpected" circumstances - a hint that pressure from the U.S. may be hurting its sales.
The comment by Shao Yang at the Consumer Electronics Show in Shanghai comes as Washington intensifies pressure on other countries to exclude Huawei Technologies from next-generation, or 5G, telecom networks where it actually is considered an industry leader.
"If we had not encountered anything unexpected, we would have become number one in the world by the fourth quarter," Huawei's chief strategist, Shao Yang, said at the Consumer Electronics Show in Shanghai.
"But now we have to wait a little bit longer to achieve that," he said, without referring directly to President Donald Trump or the trade war.