Singapore Democratic Alliance

2001: Formation

SDA was first established in 2001 by Chiam See Tong as he wanted to provide a common grouping under which different opposition parties could stand as a political coalition in elections against the ruling People's Action Party (PAP). The alliance initially consisted of his party SPP, NSP, SJP and PKMS. It was the first coalition to be formed in post-independence since 1963, after the now-defunct Singapore Alliance Party. Chiam became the first chairman of SDA. The logo of SDA is a star and four interlocking circles.^[2]

In the 2001 general election, SDA contested a total of thirteen seats consisting of three SMCs (Bukit Timah, Chua Chu Kang, Potong Pasir), and two 5-member GRCs (Jalan Besar, Tampines). In the 2006 general election, SDA contested a total of twenty seats consisting of four SMCs (Chua Chu Kang, MacPherson, Potong Pasir, Yio Chu Kang), two 5-member GRCs (Jalan Besar, Tampines), and one 6-member GRC (Pasir Ris-Punggol). SDA managed to retain the Potong Pasir SMC seat under Chiam through both elections and obtained one NCMP seat under Steve Chia in the 2001 election.^[3][4]

2007–2010: NSP left coalition, failed RP proposal to join coalition

In 2007, the NSP pulled out from the SDA in the hope of rejuvenating their party.^[5] In 2009, Chiam spoke of the possibility of having Reform Party (RP) to join the SDA.^[6] Later in 2010, Kenneth Jeyaretnam, the secretary general of Reform Party (RP), met with Chiam and discussed for RP to join SDA. RP had set out a list of 11 conditions which Chiam and his wife, Lina Loh, mostly agreed to.^[7] However, the rest of the leadership of SDA voted not to make a decision on the list of conditions.^[7][8] The discussion by the SDA council was leaked to the press and as a result, Jeyaretnam decided not to join the SDA.^[8]

In October 2010, Chiam replaced SDA's secretary general, Desmond Lim Bak Chuan, with Mohamad Hamim Aliyas during a central executive committee meeting of the SPP.^[9] SPP founder and chairman Sin Kek Tong said that Chiam's move was due to Lim's opposition to RP joining the SDA.^[9] However, in a SDA council meeting held shortly after, the council rejected the decision of Chiam, and Lim remained as the secretary general.^[10]

2011–2019 : Post-SPP withdrawal

On 2 March 2011, SPP withdrew from the coalition,^[11][12] following the decision by the SDA council to relieve Chiam as chairman, citing frequent "no-shows" at the alliance meetings.^[13] Following the pullout, SDA became a two-party alliance consisting of PKMS and SJP. The chairperson was later succeeded by SJP leader Desmond Lim.

Events that followed the separation of Chiam's SPP from SDA saw the waning of the alliance, where they fell short on winning any of the subsequent elections. In the 2011 general election, the SDA, NSP (which fielded a large slate of candidates), and SPP were unsuccessful: Lim became the only candidate forfeiting his electoral deposit (S$16,000) in the only three-cornered contest in the newly formed Punggol East SMC (a ward carved out from the neighbouring Pasir Ris-Punggol GRC, which the alliance also contested); and SDA members who joined as independents contesting in Tanjong Pagar GRC (the election's only uncontested constituency) were disqualified on nomination day.

In the 2013 by-election at Punggol East SMC, Lim contested again, but later conceded defeat during vote counting;^[14] ultimately, he garnered only 0.57% of the valid votes cast for the election, resulting him as the second candidate in history (after United People's Front candidate Harbans Singh) to have his deposit forfeited on both times;^[15] its score was also the worst-performing result in post-independence Singapore at the time,^[16] which has since superseded by the two teams, NSP and the People's Power Party (PPP), who garnered 0.43% and 0.18% of the valid votes while both contesting Tampines GRC in the 2025 election, respectively.^[17]

In the 2015 general election, SDA fielded their only team of six in Pasir Ris–Punggol GRC, but with no success.

2020–present : Failed proposed joining of coalition

Leading up to the 2020 election, four political parties: Singaporeans First, People's Power Party, Reform Party and Democratic Progressive Party, proposed to form an alliance of their own.^[18] Subsequently, the four parties decided to apply to join the SDA,^[19] but the plan did not materialize.^[20][21][22] SDA had contested the 2020 election, marked as Lim's last election leading the SDA.^[23] While the party only contested Pasir Ris-Punggol GRC, a three-cornered contest arose with the participation of a third political party, Peoples Voice. This was the second time in Singapore's election history that a multi-cornered fight had taken place in a GRC (the first being 1992's by-election under Marine Parade GRC).^[24] SDA garnered 23.67% of the votes while PV ended up losing their deposits after garnering 12.18%.^[25]

On 11 March 2025, Lim announced that he had reversed his earlier decision to step down as chairman of the SDA.^[26] Lim was supposed to handover to Harminder Pal Singh. However, due to Harminder's health issue, the Central Executive Committee (CEC) have decided for Lim to continue to lead the Alliance. On 13 April, Lim announced that a new party had joined the alliance^[27] and subsequently revealed on 23 April that Chia Yun Kai, whose party he created under Most Valuable Party, have yet to be approved by the Registry of Societies, therefore, Chia joined SJP to contest as a SDA candidate to contest for Pasir Ris-Changi GRC in the 2025 general election.^[28]

Current members

• Singapore Justice Party (Founder in 2001)
• Singapore Malay National Organization (Founder in 2001)

Former members

• National Solidarity Party (Founder in 2001 - 2011, the group eventually left after the 2011 elections)
• Singapore National Front (Founder in 2001 - 2011, the group eventually disbanded after the 2011 elections)
• Singapore People's Party (Founder in 2001 – 2020, the group eventually left after Chiam See Tong stepped down)

Parliament

More information Election, Leader ...

Election	Leader	Votes	%	Seats					NCMPs	Position	Result
				Contested			Total	+/–
				Seats	Won	Lost
2001	Chiam See Tong	75,248	12.03%	13	1	12	1 / 84	1	1 / 1	2nd	Opposition
2006		145,628	12.96%	20	1	19	1 / 84		0 / 1	3rd	Opposition
2011	Desmond Lim	55,988	2.78%	7	0	7	0 / 87	1	0 / 3	7th	No seats
2015		46,550	2.06%	6	0	6	0 / 89		0 / 3	8th	No seats
2020		37,237	1.49%	5	0	5	0 / 93		0 / 2	9th	No seats
2025		29,109	1.22%	4	0	4	0 / 97		0 / 2	7th	No seats

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Seats contested

More information Election, Constituencies contested ...

Election	Constituencies contested	Contested vote %[30]	+/–
2001	5-member GRC: Jalan Besar, Tampines; SMC: Bukit Timah, Chua Chu Kang, Potong Pasir	27.6%	—N/a
2006	6-member GRC: Pasir Ris-Punggol; 5-member GRC: Jalan Besar, Tampines; SMC: Chua Chu Kang, MacPherson, Potong Pasir, Yio Chu Kang	32.5%	4.9%
2011	6-member GRC: Pasir Ris-Punggol; SMC: Punggol East1	30.1%	2.4%
2015	6-member GRC: Pasir Ris-Punggol	27.1%	3.0%
2020	5-member GRC: Pasir Ris-Punggol	23.7%	3.4%
2025	4-member GRC: Pasir Ris-Changi	32.3%	8.6%

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By-election

More information Election, Leader ...

Election	Leader	Constituency contested	Votes	%	Seats				Result
					Contested		Total	+/–
					Won	Lost
2013	Desmond Lim	Punggol East SMC1	168	0.57%	0	1	0 / 1		Lost

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