General view of the Chinese Consulate General in Manchester
General view of the Chinese Consulate General in Manchester, Britain, October 17, 2022. Reuters

British Foreign Secretary James Cleverly said on Wednesday the treatment of a protester seen being pulled into the grounds of a Chinese consulate and beaten was "unacceptable" while the Consul-General said demonstrators had stormed its grounds.

The altercation occurred on Sunday during a demonstration against Chinese President Xi Jinping outside the consulate Manchester, northern England.

Britain on Tuesday summoned China's Charge d'Affaires in London to explain what had happened, with Cleverly saying the protests had been peaceful and legal.

"They were on British soil and it is absolutely unacceptable for this kind of behaviour," said Cleverly told broadcasters on Wednesday.

Beijing has responded by saying it had lodged representations with Britain "about the malicious harassment incident".

It was the latest diplomatic spat between Britain and China, whose relationship has soured in the last few years.

The protest, involving about 30 to 40 people including Hong Kong citizens now resident in Britain, took place at the start of a twice-a-decade congress of China's ruling Communist Party in Beijing at which Xi is widely expected to win a third leadership term.

KICKED AND PUNCHED

Footage on social media showed a man in a black cap and ponytail being hauled through a gate into the consular grounds, where he was kicked and punched by five men as he lay on the ground.

"A small group of men came out of the building and a man was dragged into the consulate grounds and assaulted," a police statement said. It said a man aged in his 30s had suffered injuries and needed hospital treatment.

Zheng Xiyuan, the Chinese Consul-General, has written to police to say he was disappointed with how they had handled the protest.

"At one point the consulate grounds were stormed by a group of protesters and members of consular staff were required to physically fend off unauthorized entry and subsequent assaults," he wrote in a letter released to media.

During a scuffle, one protester grabbed a member of staff and refused to let go, he said. Colleagues pulled them inside and "despite several of our staff attempting to pull him off, the attacker continued assaulting our staff member and so our staff were forced to disentangle his hands".

He said the protesters had been displaying offensive images including one of Xi with a noose around his neck and slogans written in Chinese reading "God Kill CPC" (Communist Party of China).

Britain has however threatened further action.

"My understanding is the Greater Manchester Police will be conducting an investigation into this and when I see the details of that investigation, I'll then decide what more we might need to do on that," Cleverly said.

Relations between Britain and China have been increasingly tense since Beijing brought in a national security law in Hong Kong, a former British colony which returned to Chinese rule in 1997 with the promise that its freedoms would be protected.

Britain has been highly critical of the law, which it says has been used to suppress dissent, while Beijing has accused London of interfering and creating trouble.

Points of contention include a British programme allowing almost three million people in Hong Kong to apply for visas, and China's move to impose sanctions on some lawmakers in Britain's ruling Conservative Party for spreading "lies" about alleged human rights abuses in the Chinese region of Xinjiang.

Britain's Conservative Party's annual conference in Birmingham
British Foreign Secretary James Cleverly takes part in a television interview, at Britain's Conservative Party's annual conference in Birmingham, Britain, October 5, 2022. Reuters