Hong Kong's largest independent trade union disbanded on Sunday, further stoking concerns over the space for civil society groups as a national security law and the sweeping powers it gives the police stifle dissent in the global financial center.

Founded in 1990, the 145,000 member Hong Kong Confederation of Trade Unions (HKCTU) voted to disband, bringing an end to the organization as authorities exert greater control on groups and unions in the business hub.

While anti-government protests in 2019 generated a new wave of labor activism in Hong Kong and triggered a 35% jump in registered trade unions, groups have been scrambling to disband since Beijing imposed the security law last year.

Fears of falling foul of the law and facing terms of up to life in jail have seen at least 29 trade unions disband since the start of this year, according to a tally by Reuters.

HKCTU vice-president Leo Tang said members of the group had received threats to their personal safety, without elaborating.

Hong Kong leader Carrie Lam has denied that the government is carrying out a crackdown on civil society, and authorities say all law enforcement actions have been based on evidence and have nothing to do with the political beliefs of those arrested.