Image copyright Reuters Image caption Benny Tai is a founder of the Occupy Central protest group

The Chinese authorities have accused British MPs of interfering in Hong Kong's affairs, Newsnight has learned.

They are trying to block an influential Westminster committee from carrying out an inquiry into the ongoing tensions in Hong Kong.

The Chinese ambassador to the UK has also tried to warn the MPs off.

It comes as thousands of activists in Hong Kong protest at Chinese government moves which they say will limit democratic elections in the territory.

In a strongly worded letter, the Chinese Foreign Affairs Committee accuses its UK counterpart of carrying out a "highly inappropriate act which constitutes interference in China's internal affairs".

The letter says it has "sent a wrong political signal to the outside world, and disrupted Hong Kong's political reform".

The letter goes on to say China will "brook no interference, either directly or indirectly, from the UK or any other external forces".

'Negative impact'

It adds that the Commons Foreign Affairs Committee's intention to carry out its inquiry "will have a negative impact on the relations between our countries".

The Chinese committee warns the MPs to "act with caution on the issue of Hong Kong, bear in mind the larger picture of China-UK relations and Hong Kong's prosperity and stability, stop interfering in Hong Kong's affairs and cancel the inquiry on UK-Hong Kong relations".

The Commons committee announced its intention to investigate in July, to consider progress made by Hong Kong in the 30 years since its handover was agreed with the UK.

The scope of the inquiry clearly set out to consider progress towards democratic reform.

The deal that the UK signed with China to transfer sovereignty of Hong Kong established the so-called basic law.

That guaranteed high degrees of autonomy and basic rights and freedoms for people living in Hong Kong.

As the co-signatory of the deal, the UK has an ongoing interest in what is happening in Hong Kong. For example, the foreign secretary reports twice a year to Parliament.

Foreign Affairs Committee chairman Sir Richard Ottaway told the BBC's Newsnight he did not "particularly want to irritate the Chinese" but he wanted them to "understand the way we work".

He said he was not offended by the letter from Chinese authorities, adding that the British and Chinese committees both had a "job to do".

"It may well be that my committee will decide that actually the Chinese are behaving perfectly reasonably," he said.

But he said if it was true that a Chinese committee was nominating a "limited number of candidates" for an election, there did appear to be a "prima facie case" that China had breached the undertakings it gave in the 1984 handover agreement.