China’s UK ambassador has urged British politicians not to “dance to the tune of the United States” and vowed “severe consequences” should MPs set foot in Taiwan.

Speaking at a press conference in London, the Chinese ambassador, Zheng Zeguang, who has been on parliament’s sanctions list since last summer, also reminded the British government of the joint communique the two countries signed in 1972, when they began to exchange ambassadors.

Zheng’s comment came as the US House speaker, Nancy Pelosi, began her controversial visit to Taiwan, over which Beijing claims sovereignty. Pelosi said her visit was to show solidarity to the vibrant Asian democracy, but in response, Beijing issued a number of warnings and threats.

China’s ministry of defence said on Tuesday that the People’s Liberation Army (PLA) had been put on “high alert” and announced a series of targeted military operations, including missile tests in the waters east of Taiwan and drills encircling the main island for four days, shortly after Pelosi leaves this week.

Tensions between China and a number of western nations – including the UK – over Taiwan have been on the rise in recent years. The Chinese envoy said some British politicians’ pledge to help “defend Taiwan” and parliamentarians’ plans visit to the island would both constitute “serious violation of the one-China principle and the [Sino-UK] joint communique”.

Zheng said: “It is … interference in China’s internal affairs that will inevitably lead to severe consequences in China-UK relations… We call on the UK side to abide by its own commitment … and not to underestimate the extreme sensitivity of the Taiwan issue, and not to follow the US’s footsteps.”

“As I said, those who play with fire will get burnt,” Zheng added, echoing the warning by his president, Xi Jinping, who last week also delivered the same line to Joe Biden, his US counterpart, during their fifth phone call.

The Guardian reported on Monday that Britain’s House of Commons foreign affairs committee is planning a visit to Taiwan later this year – probably in November or early December.

Responding to remarks about China made by Liz Truss and Rishi Sunak, the two Conservative leadership candidates, over the last few weeks, Zheng urged British politicians to “stop making up stories” and “be realistic” about the fundamentals of the bilateral relations.

The Chinese ambassador also said “the nature of the Taiwan question is completely different from Ukraine”, and that talk of “decoupling” between Chinese and British economies is “self-defeating” and will ultimately “undermine interests of [British] consumers” amid surging inflation and the ongoing cost of living crisis.

But the veteran diplomat was cautious in targeting the two candidates personally. “We will work with whoever becomes the new PM for the development of the China-UK relationship,” he said.