China's foreign ministry in Hong Kong urged the British government to stop its "so-called half-yearly report on Hong Kong", state media reported on Friday.
A spokesperson at the ministry branch said Britain's report "grossly interfered with Hong Kong affairs and China's internal affairs, and seriously trampled on international law".
Britain criticised what it said was the systematic erosion of freedoms in Hong Kong by the Chinese government and a crackdown on free speech by authorities, in its latest report on the former British colony, announced in a written statement to parliament on Thursday. The reports are issued every six months.
In a separate statement, the Hong Kong government said late on Thursday that it refuted the "slandering remarks and ill-intentioned political attacks" made in Britain's report.
"The Hong Kong special administrative region is an inalienable part of the People's Republic of China," the statement said, adding that the government urged Britain to "respect the basic norms governing international relations and stop interfering" in the city's affairs.
(Reporting by Liz Lee in Beijing and Farah Master in Hong Kong; Editing by Christopher Cushing and Gerry Doyle)