China has warned the UK not to "interfere in its domestic affairs" amid a growing diplomatic row over the recent protests in Hong Kong.
Its UK ambassador said relations had been "damaged" by comments by Foreign Secretary Jeremy Hunt and others backing the demonstrators' actions.
Liu Xiaoming said those who illegally occupied Hong Kong's Parliament should be "condemned as law breakers".
The ambassador was later summoned to the Foreign Office over the remarks.
A Foreign Office spokesman said Sir Simon McDonald, permanent under secretary and head of the diplomatic service, told the ambassador his comments were "unacceptable and inaccurate".
Earlier, Prime Minister Theresa May said she had raised concerns with Chinese leaders.