[4] At the 1991 General Election, SDP members Ling How Doong and Cheo Chai Chen won their seats at Bukit Gombak and Nee Soon respectively, giving the party a total of three MPs.

Among others, it emphasises stronger protections for civil liberties and promotes social liberal approaches to issues as well as changes to education, healthcare and housing policies.

[12] These disputes, which included disagreements over leadership style and party direction, were exacerbated by Chiam's attempt to censure Chee following a hunger strike.

[17] Following these events, supporters of Chiam left the SDP and formed the Singapore People's Party (SPP) in 1994, with Sin Kek Tong as its pro-tem leader.

Dr. Paul Tambyah, Chairperson of the SDP, commented on the new CEC line-up, stating that it comprises a balanced mix of experienced party veterans and dynamic young members, all committed to fostering a more democratic Singapore.

Secretary-General Dr. Chee Soon Juan emphasized the importance of a unified strategy for public engagement and planning as the party prepares for the upcoming General Election, expected in the latter half of 2024.

[27] Besides Chiam and Ling, the SDP also fielded Ashleigh Seow (the son of former Solicitor-General Francis Seow), businessmen Jufrie Mahmood, Cheo Chai Chen and Ng Teck Siong, sales manager Kwan Yue Keng, bank clerical assistant Mohd Shariff Yahya, teacher George Sita, financial futures trader Jimmy Tan, former PAP MP Low Yong Nguan, businesswoman Toh Kim Kiat, construction supervisor Francis Yong Chu Leong, shipping manager Chia Ah Soon and director Sin Kek Tong, the later who would found Chiam's spin-off party of Singapore People's Party.

The SDP chose to highlight its objections to some controversial government policies such as the sharp increase of ministers' salaries, the cost of healthcare, university education, transport and the GST.

[31] Along with Worker's Party would-be leader Low Thia Khiang electing in Hougang, the opposition won a combined four parliament seats, then the largest representation since 1963.

[32] In 1992, Chiam recruited Chee Soon Juan, a psychology lecturer at the National University of Singapore (NUS), to be an SDP candidate for a by-election in the Marine Parade Group Representation Constituency.

[33] The party continued its preparations for the 2006 general election, choosing to target then-Health Minister Khaw Boon Wan in Sembawang GRC over the National Kidney Foundation Scandal and to ride on the public backlash at the time.

The Sembawang team was led by Chee Siok Chin, along with businessmen Christopher Neo, Isa Abdul Aziz and Yong Chu Leong, marketing manager Gerald Sng Choon Guan and administrator Narayanasamy Gogelavany, while the party's chair, Ling How Doong, was fielded in Bukit Panjang SMC.

The SDP's final vote share for Sembawang and Bukit Panjang was 23.3% and 22.8% respectively,[35][36] marking a slight improvement in results as compared to 2001, but still far short of the national average of 33.3%.

The trial PP vs. Chee Soon Juan and 18 others began on October 23, 2008, with the defendants charged on two counts of violating Section 5(4)b Chapter 184 of the Miscellaneous Offences (Public and Nuisance) Act.

Former senior civil servant Tan Jee Say, private school teacher Michelle Lee Juen, psychiatrist Ang Yong Guan and social activist Vincent Wijeysingha made up the SDP's team for Holland–Bukit Timah GRC.

The team fielded there consisted of academic and former WP member James Gomez, party Assistant-Secretary-General John Tan, entrepreneur Jarrod Luo, former unionist Sadasivam Veriyah and businessman Mohd Isa.

Former ISA detainee Teo Soh Lung and party treasurer Gerald Sng were also introduced to the media and were fielded in the constituencies of Yuhua and Bukit Panjang respectively.

Among the issues brought up by the party prior to nomination day were: the heavy influx of foreigners into Singapore, Vivian Balakrishnan's mismanagement of the Youth Olympic Games[42] and the loss of sinking funds in the PAP run town councils in Holland–Bukit Timah and Bukit Panjang.

On 20 March 2016, SDP announced that Chee would stood as a candidate for the forthcoming by-election for the ward of Bukit Batok SMC held on 7 May, after incumbent David Ong vacated his seat due to an extramarital affair involving another grassroots leader.

Former SDP member Kwan Yue Keng also stated his intention to contest as independent, but later withdrew upon Chee's successful nomination, as part of an agreement from the People's Power Party to prevent a walkover.

On 7 August 2017, former Parliamentary Speaker Halimah Yacob vacated her seat in Marsiling-Yew Tee GRC in order to contest that year's presidential election.

[61] While the seat remain vacant, the grassroots advisor (which was linked to People's Association) was replaced by Chua Chu Kang GRC MP Zaqy Mohamad the day after.

[63] On 14 September (the same day Yacob was sworn as president after the election went uncontested[64]), the party's assistant treasurer Wong Souk Yee filed a lawsuit for a by-election (intended to occur on 15 January 2018 as cited in a pre-trial conference) to be called.

[86] On 12 April, the party announced that they will relocate their headquarters from Ang Mo Kio after eight years on 11 November to the "western half of the island",[87] later revealing to be WGECA Tower.

[92] In his presentation, Dr Chee also pledged to have the party form a working committee in collaboration with economists and labour policy experts to develop credible proposals with actionable solutions for fellow Singaporeans.

The session concluded with a panel discussion between Vice Chairman Bryan Lim Boon Heng (林文兴), CEC Member Dr James Gomez, and Party Treasurer Surayah Akbar SDP.

Moderated by Head of Communications Min Cheong-Subramaniam, the speakers explored topics ranging from the party’s response to the recently-published Forward SG report, voter engagement strategies, the changing socio-political landscape, the impact of social media and new technology, and the cogency of the SDP’s policies.

[93] On August 3rd, 2024, the Singapore Democratic Party (SDP) celebrated a significant milestone — 44 years since founding — with a memorable gala dinner at the prestigious Raffles Town Club.

Distinguished guests included representatives from global and regional partners, such as delegates from the Council of Asian Liberals and Democrats and its constituent parties.

Inspiring speeches were delivered by Dr. Chee Soon Juan and Dr. Paul Tambyah, who reflected on the Singapore Democratic Party journey and shared their vision for the future.