The dispute over whether Huawei should be allowed to participate in building the UK's 5G telecoms network has escalated, with an intervention from the Chinese ambassador to the UK, and a growing rift between Prime Minister Theresa May and some of her Cabinet colleagues.

A prominent national newspaper carried a signed article by Liu Xiaoming, in which he argued that Britain should resist external pressure over decisions on Chinese companies and make independent choices.

"This week has seen the start of a heated debate over what decision to make with regard to the development of the UK’s 5G network and whether the company represents a security threat," he wrote. "But what seems like a simple choice between different 5G suppliers actually hinges on three, very important, binary decisions that face the UK."

First, will the UK choose independent decision-making or not? Countries of global influence, like the UK, make decisions independently and in accordance with their national interests, Liu argues, and should resist pressure and act according to its national interest on 5G.

The second decision for the UK is whether it chooses open and free trade, at a time when protectionism is on the rise. And third, he writes that the UK needs to decide whether to choose win-win cooperation or not. 

Last week it was reported in the UK press that the UK government is leaning towards allowing Huawei to work on some less critical parts of the 5G infrastructure, though not the core of the network.

This was leaked from a National Security Council meeting chaired by Prime Minister Theresa May, which has led to an unprecedented investigation to identify the leaker.

And over the weekend British Foreign Secretary Jeremy Hunt openly defied May by publicly coming out against Huawei involvement.

Britain should be cautious about allowing Huawei to help build the UK's 5G network, because it is legally obliged to cooperate with the Chinese intelligence services, Hunt warned. The Foreign Secretary is viewed as one of the front runners for leadership of the Conservative Party, as pressure grows to remove Theresa May.

Speaking ahead of a trip to Africa, Hunt said, "We are right to have a degree of caution about the role of large Chinese companies because of the degree of control the Chinese state is able to exercise over them in the way that would not be possible if they were large Western companies.”

The row over Huawei is also casting a shadow over the upcoming state visit to the UK by US President Donald Trump, which is scheduled for early June.