Tat Cheng was a member of the Civic Party (香港公民黨) since 2012 and served as its vice secretary-general from 2016 to 2018. [x] He was elected as the Eastern District Councillor in 2015 and re-elected in 2019. [1]

Cheng graduated from the Hong Kong Polytechnic University (香港理工大學) with a bachelor's degree in Social Policy and Adminstration. In 2016, while balancing his responsibilities as a district councilor, Cheng began pursuing a Doctor of Jurisprudence (JD) degree at the City University of Hong Kong (香港城市大學). He believes that studying law would enrich his knowledge and empower him to serve the people. [2] He then pursued a Postgraduate Certificate in Laws at CityU, citing that it can help protesters obtain bail and navigate the judicial process.

Cheng had served in different positions in the Civil Party from 2012 to 2020. In the 2015 District Council election, he won the seat in the Tanner (丹拿) constituency, previously held by Desmond Lee (李汝大), a pro-Beijing politician who served the council for nearly 30 years. He was re-elected in the 2019 District Council Elections, in which the pro-democracy camp drew a landslide victory. [3] Cheng's political agenda focused on the development plans and cultural conservative initiatives within North Point (北角) and beyond, and giving public speeches on the party's focused issues. [4]

In July 2020, Cheng participated in the pro-democracy primaries where he garnered 11,090 votes — 12.26% of the electorate — and secured a nomination for the upcoming legislative elections.[5] However, on Jul. 30, 2020, the Hong Kong government disqualified the nominations of 12 pro-democracy candidates, including Cheng, citing the pan-democrats previous calls for foreign governments to impose sanctions on Beijing, as well as their pledge to veto the government’s budget.[6] He left the party on Dec. 15, 2020. [7]

Following Cheng's participation in the primaries in July 2020, he was arrested on January 6, 2021, along with 54 other pro-democracy figures, on suspicion of conspiracy to commit subversion under the National Security Law. [8] He was then granted bail on March 13, 2021. [9]

Cheng pleaded not guilty to the charges brought against him and was found guilty on May 30, 2024. [10] On Nov. 19, 2024, the court ruled that he was an active participant in the primary election and ultimately sentenced him to 6 years and 6 months in prison. [11]