The UK risks losing its position as a world leader in mobile connectivity, Britain's mobile operators are warning.

In a draft letter to Cabinet Secretary Mark Sedwill, seen by the BBC, operators will urge the government to clarify its position over Huawei.

The letter asks for an urgent meeting between industry leaders and the government to discuss their concerns.

Operators say they can't invest in infrastructure while uncertainty over the use of Chinese technology persists.

The companies are planning to send the letter to government as soon as this week.

They are concerned at the government's inability to decide whether Huawei technology will be approved for use in new 5G networks.

A government spokesperson said: "The security and resilience of the UK's telecoms networks is of paramount importance. We have robust procedures in place to manage risks to national security and are committed to the highest possible security standards.

"The Telecoms Supply Chain Review will be announced in due course. We have been clear throughout the process that all network operators will need to comply with the government's decision."

Huawei is the world's leading supplier of next generation connectivity equipment, but it has faced a backlash from the US.

The US government has already banned the use of Huawei technology after citing concerns that the company may present a security threat by allowing the Chinese government a way to snoop on critical infrastructure.

The US has also threatened to limit intelligence co-operation with any country that allows Huawei equipment to be used in its own networks.

Earlier this year there were unconfirmed reports that the government was considering allowing Huawei equipment into the periphery of new mobile networks, but not into the "core" of systems that could end up managing crucial services such as hospitals, police forces and the energy network.

BT-owned mobile operator EE said it had delayed the launch of Huawei's 5G phones "until we get the information and confidence and the long-term security that our customers … are going to be supported".

Vodafone has also announced it is suspending orders of Huawei 5G handsets.

In perhaps the biggest blow to Huawei, British firm ARM, which designs processors used in most mobile devices worldwide, has also said it may suspend ties with Huawei.

Huawei has found itself on the front line of the trade war between the US and China.

The company insists that it poses no security threat to any of its customers.

Huawei says suggestions to the contrary are a smokescreen for frustrating China's attempts to emerge as a leading designer and provider of high tech equipment, rather than assembling the nuts and bolts of technology designed in the US and Europe.