His political involvement commenced with grassroots work with various incumbent members of parliament and constituencies, especially the now defunct Jalan Besar GRC. Tong was fielded by the People's Action Party as a candidate in the group representation constituency of the newly formed Moulmein-Kallang GRC. He was elected, with the team garnering 44,828 votes or 58.56% of the total votes cast. Tong previously served as a member of parliament for the sub-electoral division of Jalan Besar, but it has since been split up and merged with Kolam Ayer, Kampong Glam and Whampoa in 2015.
He ran in Marine Parade GRC against the Workers Party in the 2015 General Election and was elected with 67.02% of the vote.
The party affiliation of each member is indicated right after the constituency he or she represents. PAP: People's Action Party; WP: The Workers' Party
The NCMPs listed above are from the WP, while NMPs do not belong to any party.