China warned Britain on Wednesday that it must "refrain from further interference" in Hong Kong's protests or risk "further damaging" its relationship with Beijing.
China has appeared irked by Britain's public rebukes over the unprecedented anti-Beijing demonstrations that have rocked Hong Kong in recent weeks.
"I do hope that the British government will realise the consequences and... refrain from further interference, from further damaging the relationship," China's UK ambassador Liu Xiaoming told a press conference broadcast by Sky News.
Britain said it had summoned the ambassador for a meeting later on Wednesday to discuss the protests in the former British colony, a source at the Foreign Office told AFP.
The ambassador warned Foreign Minister Jeremy Hunt, who is in the running to become Britain's new prime minister, to "respect sovereignty, territorial integrity and non-interference of internal affairs.
"As long as these principles are violated, there will be a problem in the relations between our two countries.
"It's very disappointing when senior officials of his (Hunt's) calibre show support for these law-breaking people," he added, referring to Hunt's comments supporting those protesting against China.
Hunt tweeted that "good relations between countries are based on mutual respect and honouring the legally-binding agreements between them," saying those values would "preserve the great relationship" between the two countries.
Prime Minister Theresa May earlier said she had raised "concerns" over the protests, with Liu Xiaoming criticising "hypocritical" British politicians.
"Instead of condemning it, they showed support, sympathy to these law breakers," he said.
Under the terms of the 1997 handover deal from British to Chinese rule, Hong Kong enjoys rights and liberties unseen on the mainland. But protesters accuse Beijing of reneging on that deal with the help of unelected leaders.