Rumours first surfaced online at the start of the year. In early February, Yaw resigned from WP's executive council, where he held the post of treasurer, with no explanation. This failed to appease Low and the party leadership, which voted in favour of the expulsion. According to Singapore's laws, a MP loses his seat if he is no longer member of the party that he was elected under. Having relocated overseas, Yaw declined to appeal against WP's decision. His four-month tenure as a parliamentarian officially ended on 14 February 2012 and was the shortest ever in Singapore history.

Within three months, Prime Minister Lee Hsien Loong advised President Tony Tan to issue a writ, despite an earlier refusal to commit to holding a by-election. He also criticised WP for letting the voters down. Before this, on 2 March 2012, an Hougang resident filed an affidavit to have mandatory by-elections within three months of a vacated seat or within reasonable time as decided by the courts, rather than to allow a PM to have unfettered discretion. The case was ultimately canned by the Court of Appeal.

WP fielded a member of the defeated East Coast GRC team in last year's GE. He faced the same candidate PAP fielded last year, who had remained grassroots leader in the ward. Other opposition parties announced that they would stay out of the fray. Poh Lee Guan and Zeng Guoyuan, both former WP candidates in the 2011 and 1991 GEs respectively, were issued political donation certificates although neither contested in the end. Poh, an existing WP member, was later expelled from the party for making a unilateral decision to apply for a certificate to be WP's "back-up candidate".

During the campaign, Deputy PM Teo Chee Hean questioned Png Eng Huat's honesty over his statements on rejecting the Non-Constituency MP seat, while Low and WP leaders took issue with Desmond Choo's "independent voice" claim.

For the first time in Singapore's history, the required election deposit sum saw an adjustment in a by-election and also a reduction after the salary of ministers and MPs were cut earlier in the year. With a margin close to 30% the last time, WP won easily with a negligible swing.