LONDON (Reuters) - Britain rejects China’s assertion that their joint declaration on the governance of Hong Kong is a historic document which is no longer valid, junior foreign minister Alan Duncan said on Tuesday.

There were violent protests in Hong Kong on Monday, marking 22 years since the former British colony returned to Chinese rule. China said that Britain no longer has a say in what goes on in the city, where people have protested against a bill to allow extraditions to China.

“We reject the Chinese government’s assertion that the joint declaration is an historic document, by which they mean it is no longer valid and that our rights and obligations under that treaty have ended,” junior foreign minister Alan Duncan told lawmakers.

“Our clear view is that the Sino-British joint declaration of 1984 obliges the Chinese government to uphold Hong Kong’s high degree of autonomy and its rights and freedoms and we call on the Chinese government to do so.”