The national security bill buttresses Macau's Committee for Safeguarding National Security (CDSE), which was created in 2018 to support the Chinese city's leader in security matters.

Macau, a former Portuguese territory which was handed back to China in 1999, has its own legal system largely based on Portuguese law, but enacted national security legislation in 2009 and widened its powers in 2023.

Under the bill passed on Thursday, defence lawyers involved in national security cases will be required to obtain permission from national security officials because of the possibility that some case information could be classified.

Macau's Legislative Assembly said the bill was passed unanimously.

The bill "further strengthens the top-level framework for safeguarding national security", the city's government said in a statement, and demonstrates "the successful implementation of the principle 'patriots governing Macao'".

Some analysts have warned that the regulation could undermine the functioning of government departments and the rights guaranteed by Macau's mini-constitution.

Macau authorities arrested former legislator Au Kam-san in July 2025 for alleged foreign collusion in the first known use of the national security law in the Chinese casino hub.