An employee of the UK consulate in Hong Kong who was tortured by Chinese authorities will be granted a visa to rebuild his life in Britain, it emerged on Wednesday as senior Conservatives urged Boris Johnson to extend similar freedoms to all UK nationals in the former colony.

The move came as China on Wednesday warned London that continuing to interfere in Hong Kong and China's internal affairs "will only harm the UK’s interests."

“China firmly objects to the UK’s comments related to the matter, and we express strong indignation toward the UK’s false actions and comments on all issues relating to Hong Kong," Geng Shuang, a foreign ministry spokesman, said in Beijing.

Earlier Dominic Raab, the foreign secretary, summoned the Chinese ambassador in the UK “to express our outrage at the brutal and disgraceful treatment" of Simon Cheng, who was chained, beaten, and forced into stress positions during a two-week long ordeal.

Ambassador Liu Xiaoming told the British government that Mr Cheng was detained for disturbing public order and that he "confessed all his offences and all his lawful rights and interests were guaranteed in accordance with the law," according to an embassy spokesperson.