She became known for her strong antipathy towards colonialism and corruption, as well as for her work for the underprivileged.
She took the main role in the 1966 Kowloon riots when she opposed the Star Ferry fare increase which later turned into riots and faced accusations of inciting the disorder.
She fought for gay rights, better housing, welfare services, playgrounds, bus routes, hawker licences and innumerable other issues and her campaigning is credited with leading to the establishment of the Independent Commission Against Corruption (ICAC) in 1974.In the run up to the 1997 handover of Hong Kong to China and the midst of the Sino-British conflict on the 1994 Hong Kong electoral reform, Tu found favour with the Chinese Communist authorities, and took a seat on the Beijing-controlled Provisional Legislative Council, from December 1996 to June 1998, after losing both her seats in the Urban and Legislative Councils in 1995 to another prominent democrat Szeto Wah.
In post-1997 Hong Kong, although without a formal public role, Tu consistently supported the SAR government and policies including the controversial Basic Law Article 23 legislation.
She died in Hong Kong on 8 December 2015 at the age of 102.