China's top decision-making body approved sweeping new changes to Hong Kong's electoral system on Tuesday, Xinhua news agency reported.
The measures are part of Beijing's efforts to consolidate its increasingly authoritarian grip over the former British colony.
It follows the introduction of a national security law last year which critics see as a tool to crush dissent.
China's rubber-stamp parliament first approved the plan during the National People's Congress earlier this month.
The reforms are intended to ensure that only "patriots" govern the city.
There will be a vetting committee which will assess a candidate's loyalty to Beijing.
The changes will see the number of directly elected representatives fall to 20 from 35,
but the size of the legislature will increase to 90 from 70.
An election committee - responsible for selecting the chief executive - will increase from 1,200 to 1,500.
The representation of 117 community-level district councillors in the committee will be scrapped.
Chinese authorities have said the shake-up will get rid of "loopholes and deficiencies" that threatened national security during anti-government unrest in 2019.
But critics say the changes leave the democractic opposition with the most limited space it has ever had since the handover.