China told Britain to keep its hands off Hong Kong on Wednesday while London called for Beijing to honour the agreements made when the city was handed over in 1997, escalating a diplomatic spat over the former British colony.
Beijing denounced British Foreign Secretary Jeremy Hunt as "shameless" and said it had made a diplomatic complaint to London after he warned of consequences if China neglected its commitments to guarantee basic freedoms.
"In the minds of some people, they regard Hong Kong as still under British rule. They forget ... that Hong Kong has now returned to the embrace of the Motherland," China's ambassador to London, Liu Xiaoming, said.
"I tell them: hands off Hong Kong and show respect. This colonial mindset is still haunting the minds of some officials or politicians," Liu told reporters.
The growing war of words between China and Britain follows mass protests in Hong Kong against a now suspended bill that would allow extradition to mainland China.
Hundreds of protesters in the former British colony besieged and broke into the legislature on Monday after a demonstration marking the anniversary of return to Chinese rule.
China called the violence an "undisguised challenge" to the "one country, two systems" model under which Hong Kong has been ruled for 22 years.
On Tuesday, Hunt warned of consequences if China did not abide by the Sino-British Joint Declaration in 1984 on the terms of the return of Hong Kong, which allows freedoms not enjoyed in mainland China, including the right to protest.
"We can make it clear we stand behind the people of Hong Kong in defence of the freedoms that we negotiated for them when we agreed to the handover in 1997 and we can remind everyone that we expect all countries to honour their international obligations," Hunt told Reuters.
Hunt is one of two contenders vying to replace Theresa May as British prime minister and his rival Boris Johnson told Reuters on Wednesday that he also backed the people of Hong Kong "every inch of the way".
The comments clearly irked Beijing. China's London envoy scolded Britain and said meddling in Hong Kong would cause a "problem in the relationship" between them.
"The UK government chose to stand on the wrong side: it has made inappropriate remarks not only to interfere in internal affairs of Hong Kong but also to back up the violent law-breakers," Liu said.
Earlier, Foreign Ministry spokesman Geng Shuang chided Hunt, saying that only after Hong Kong's return to China did its people get an "unprecedented" guarantee about democracy and freedom.
"To say that the freedoms of Hong Kong residents is something Britain strived for is simply shameless," he told a news briefing. "I would like to ask Mr. Hunt, during the British colonial era in Hong Kong, was there any democracy to speak of? Hong Kongers didn't even have the right to protest."
China had lodged "stern representations" with Britain both in Beijing and London about Hunt's remarks, he added.
Britain said it had summoned Liu to the foreign office following his "unacceptable" comments, a government source said.
"Message to Chinese govt: good relations between countries are based on mutual respect and honouring the legally binding agreements between them," Hunt said on Twitter after Liu's media briefing.
"That is the best way to preserve the great relationship between the UK and China."
The turbulence in Hong Kong was triggered by an extradition bill opponents say will undermine Hong Kong's much-cherished rule of law and give Beijing powers to prosecute activists in mainland courts, which are controlled by the Communist Party.
Hong Kong's Beijing-backed leader Carrie Lam had strongly promoted the bill, but suspended it on June 15 in the face of public protests against it. Critics have called on her to officially kill the bill, but she has resisted.
Britain and China had been seeking to reset ties after a row over the disputed South China Sea last year, with Chinese Vice Premier Hu Chunhua visiting London last month to oversee the start of a link between its stock exchange and that of Shanghai.
Confrontation and lawlessness in Hong Kong could damage its reputation as an international business hub and seriously hurt its economy, China's top newspaper, the People's Daily, said in an editorial.
"It will not only serve no purpose, but will also severely hinder economic and social development," the ruling Communist Party's official paper said, denouncing what it called artificially created division and opposition.
China has blamed Western countries, particularly the United States and Britain, for offering succour to the protests.
In an editorial, the official China Daily, an English-language newspaper Beijing often uses to send its message to the world, condemned "outside agitations".
"What has also been notable is the hypocrisy of some Western governments - the United States and United Kingdom most prominently - which have called for a stop to the violence, as if they have had nothing to do with it," the paper said.
"But, looking back at the whole protest saga, they have been deeply involved in fuelling it since its inception."