He was a core member of
Scholarism which was formed in 2011 to launch campaigns against the proposed
Moral and National Education which was seen as biased pro-Communist curriculum and became the spokesman of the group. The campaign successfully mobilised the thousands in protest and led to the turndown of the curriculum by the government in September 2012. Cheung was later enrolled to the
Chinese University of Hong Kong, studying Politics and Public Administration. He became the president of the Student Union in 2014 and the member of the
Hong Kong Federation of Students (HKFS). He was actively involved in the
massive Occupy protests in 2014 against the
Beijing's decision on the framework of the
2017 Chief Executive election. He became one of the nine leading figures arrested in 2017 for initiating the illegal assembly. He led the seven-member "Student United 2017" running in the
Election Committee subsector elections in December 2016 on the capacity of the former member of the Chinese University's Senate but his candidacy was barred by the Returning Officer of the
Electoral Affairs Commission because of his "insufficient connection" with the Higher Education subsector. In the
2018 New Territories East by-election, Cheung announced his candidacy and joined the pro-democracy primary, running against
Gary Fan of
Neo Democrats and
Kwok Wing-kin of the
Labour Party. Cheung was elected to public office for the first time during the
2019 Hong Kong District Council elections, winning a seat in
Yuen Lung. He defeated incumbent
Wilson Wong by 900 votes. On 22 October 2021, Cheung decided to resign as district councillor ahead of oath-taking, for health reasons because he was diagnosed with
liver tumor. Cheung defected to the
pro-Beijing camp after his resignation, and joined Basic Law Student Centre. ==References==