Hong Kong’s legislative assembly descended into chaos on Saturday as lawmakers for and against amendments to the territory’s extradition law clashed over access to the chamber.

At least one lawmaker was taken from the chamber on a stretcher after apparently fainting during the morning melee, in which legislators pushed and shoved each other on the floor and in an adjoining hallway.

The amendments have been widely criticised as eroding the semi-autonomous Chinese territory’s judicial independence by making it easier to send criminal suspects to mainland China, where they could face vague national security charges and unfair trials.

Hong Kong residents protest at plans for extradition to China Read more

Under the “one country, two systems” framework, Hong Kong was guaranteed the right to retain its own social, legal and political systems for 50 years after its handover from British to Chinese rule in 1997. However, China’s ruling Communist party has been seen as increasingly reneging on that agreement by forcing through unpopular legal changes.

Legislators in the pro-Beijing camp attempted to seat Abraham Razack, also known as Abraham Shek, who had been named earlier in the week to replace a pro-democrat, James To Kun-sun, as head of the bills committee. To had stalled passage of the legislation over two sessions and Razack was seen as the best chance to push it through before the July recess.

Facebook Twitter Pinterest A pro-democracy lawmaker scuffles with security guards. Photograph: Vincent Yu/AP

Pro-democracy legislators continued to claim To was the legitimate head of the committee. Both they and their opponents had scheduled rival meetings on the same topic in the same legislative council meeting room on Saturday, starting 30 minutes apart.

The amendments would expand the scope for the transfer of criminal suspects to China and remove the legislature’s right to scrutinise individual extradition decisions filed by Hong Kong’s chief executive. They could also open the way for further measures to erode Hong Kong’s civil liberties, including the passage of anti-subversion legislation.

Tens of thousands of people marched against the extradition law amendments in Hong Kong last month and numerous legal, professional and human rights organisations have voiced their opposition. They say the amendments would undermine not just Hong Kong’s legal independence but also its attractiveness as a centre for international business.