Hong Kong’s Legislative Council unanimously passed a new national security law that expands the government’s power to crush dissent.

The Safeguarding National Security Law passed on Tuesday includes new measures on treason, espionage, external interference, state secrets and sedition.

“Today is a historic moment for Hong Kong,” said Hong Kong Chief Executive John Lee, who added that the law punishing five major crimes would go into effect on March 23.

It grants the government more power to quash dissent, widely seen as the latest step in a sweeping political crackdown triggered by pro-democracy protests in 2019. It comes on top of a similar law imposed by Beijing four years ago, which has already largely silenced opposition voices in the financial hub.

Critics say that the major piece of legislation, known as Article 23, further threatens the China-ruled city’s freedoms.

The 90-seat council stacked with pro-China loyalists was first presented with the bill on March 8, following a monthlong public consultation, with Hong Kong’s leader calling for it to be enacted at “full speed”.

Eighty-eight lawmakers and the legislative council president voted unanimously to enact the legislation.

The law threatens stringent penalties for a wide range of actions authorities call threats to national security, with the most severe – including treason and insurrection – punishable by life imprisonment. Lesser offenses, including the possession of seditious publications, could also lead to several years in jail. Some provisions allow criminal prosecutions for acts committed anywhere in the world.

Legislative Council President Andrew Leung said he believed all lawmakers were honoured to have taken part in this “historic mission.”