Yau was soon disqualified from the office due to her oath-taking controversy, followed by Lau Siu-lai who was also disqualified for her oath-taking manner. Two by-elections were held in March and November 2018 where pro-Beijing candidates Vincent Cheng of the DAB and independent Chan Hoi-yan surprisingly both beat the pro-democracy candidates, first times pro-Beijing camp won a majority in a direct election in more than 20 years. Chan, however, was unseated in 2020, as the court viewed Lau Siu-lai's disqualification from running in the November 2018 by-election was unlawful.