District Council Sin's political career began in 1985 when he was first elected to the
Kwai Tsing District Board. He was re-elected in subsequent elections, remaining in this role until 2003. Between the years 1994–1999, Sin served as the chairperson of the board. In 2011, Sin was one of the contenders in the
district council election, representing the
Tai Hang constituency. He got 40.9% of the votes, losing to Wong Chor-fung of the
New People's Party (NPP). In 2014, Sin participated in the by-election for the
South Horizons West constituency, where he got 22.9% of the votes and lost to Judy Chan from the NPP. In 2019, Sin contested in the
district council election for the
Wah Lai constituency. He won the seat with 51.93% of the votes, defeating
pro-Beijing incumbent Wong Yiu-chung. He also became chairperson of the Kwai Tsing District Board again, starting in January 2020.
Legislative Council In 1995, Sin ran the
Hong Kong legislative election for the
New Territories South constituency, winning dominantly with 70.74% of the votes over two other candidates. In 1998, Sin participated in the
legislative election, representing the
Information Technology functional constituency. He was elected to the Legislative Council with 63.71% of the votes. Sin was re-elected in
2000 and
2004 within the same constituency.
Political activities Sin served as an executive committee member in the
United Democrats of Hong Kong (UDHK) between the years 1990–1994. In December 2012, Sin contested in the
leadership election of the party, following the resignation of
Albert Ho in the aftermath of the
2012 Legislative Council election. Sin lost narrowly to
Emily Lau, who had 149 votes to his 133 votes. In 2007, Sin was awarded the
Silver Bauhinia Star for his contributions to public affairs. During his political career, Sin had advocated for
human rights, economic prosperity, and free flow of information in Hong Kong. He introduced numerous initiatives to develop the city's IT and telecommunications industries. On 18 April 2020, Sin was among the 15 prominent
pro-democracy figures arrested in Hong Kong. His arrest was made based on the claim that he took part in an unauthorized assembly on 1 October 2019 during the
anti-extradition bill protests. On 10 June 2022, Sin, along the two other pro-democracy figures, had his
Silver Bauhinia Star honour removed, and his Justice of the Peace appointment was revoked by the government due to his jail sentences related to anti extradition-bill protests. == Personal life ==