China’s ambassador to Britain Liu Xiaoming will be retiring soon and replaced by foreign vice-minister Zheng Zeguang.

The development was announced by Tam Yiu-chung, Hong Kong’s delegate to the National People’s Congress Standing Committee, after a session of the committee on Saturday.

Zheng, 57, a US affairs specialist had been tipped to replace the current ambassador to the US, Cui Tiankai, 68, who has also reached retirement age.

Both Zheng and Liu are from Guangdong province. Zheng started his diplomatic career in 1986, and has concentrated on US issues since 1990.

He has served as the foreign ministry’s director of North American affairs and as a counsellor in the US embassy between 2005 and 2008. In 2015 he was promoted to foreign vice-minister.

Earlier this month he summoned the US chargé d’affaires Robert Forden to protest against US sanctions on 14 members of the National People’s Congress Standing Committee over the Hong Kong national security law, which critics say undermines the city’s freedoms and autonomy.

“Sending him to the UK means Zheng will not be posted to the US,” said Pang Zhongying, an international specialist at the Ocean University of China. “And it seems that Zheng has reached the top of his career with the posting to UK”.

Liu, 64, has been the envoy to the UK since 2010 and has become known for his outspoken defence of the country.

In 2013, he compared militarism in Japan as Lord Voldemort, the villain in the Harry Potter stories.

In July, Liu said the decision to ban the use of Huawei equipment in the national 5G mobile network is a “dark day for the UK because you will miss the opportunity to be a leading country in 5G”.

The change at the London embassy comes amid worsening relations between the two countries and diplomatic observers said Zheng will face a challenging task, especially in the wake of increased US pressure on Beijing and the recent Brexit deal.

China has also been angered by the British decision to give residency rights to Hongkongers who hold British National (Overseas) passports and a pathway to citizenship.

Wang Yiwei, a professor of international relations at Renmin University, said the UK will need to focus on ties with both US and China to compensate for the possible loss of access to European markets following Brexit.

He said the financial services sector used to play a key part in China-UK relations, but this is now affected by the China-US rivalry and other factors.

“China is hoping to gain the support of those in the financial sector who advocate for doing business with China in the financial sector to counterebalance those who emphasis national security and siding with the US,” he said.

“Joe Biden will not immediately change some of [Donald] Trump’s policies towards China after he takes office. China will have to watch Biden for a while and then choose the Chinese ambassador to the US when the time comes”.

Pang said China wants to maintain relations with the UK, as it holds the Group of Seven presidency next year and will host the United Nations Climate Change Conference.

“China will need to explore a new relationship with the UK after Brexit,” he said.