The WP sits on the centre-left of the political spectrum and is currently the largest and oldest opposition party in Parliament, having contested every parliamentary election since 1959 against the dominant PAP.

The WP was founded in 1965 by David Marshall, having previously led the more left-wing Labour Front (LF) to victory in 1955, forming a minority government and becoming the first Chief Minister of Singapore.

[8] In recent years, members of the WP have worn light blue uniforms during political campaigns to represent the party's support for blue-collar workers.

Their electoral debut was mostly a success as the party elected four members (out of the five contested) to the City Council; however, in 1958, Kallang ward incumbent Chang Yuen Tong resigned, and subsequently lost their seat to PAP as a result of their by-election defeat.

Marshall was also eager to assist the workers to prevent the political enslavement of trade unions and to revive the struggle against colonialism in seeking complete independence preferably within and, if necessary, without the Federation.

Marshall's stand on merger was that: "... Singapore should seek equal privileges and rights for its citizens in the new federation but surrender autonomy in education and labour, since different policies in these crucial areas would undermine the stability of Malaysia in the long run.

He further maintained that if Singapore could not negotiate for a complete merger, she should seek independence on her own, a proposition which drew gales of laughter from the Legislative Chamber at that time.

Singaporeans would in his view, be no more than favoured foreigners in the Federation, permitted to live and work there without visas, but also without the important constitutional guarantees that immigration barriers would not be raised against them.

Marshall later stated on 20 August 1962: "... issued a statement to advise his Executive Council and party members to accept the White Paper proposals for merger, but continued to oppose the Government on the referendum urging the people to cast blank votes on the grounds that it was undemocratically conducted.

On 13 October 1981, Devan Nair vacated his Anson seat to assume his role as the nation's third President, and precipitated the by-election; on 31 October, the party's victory was noted as historic as candidate Jeyaretnam became the first opposition MP-elect to be elected in Parliament with 51.9% (7,012) of the valid votes cast, beating PAP's Pang Kim Hin's 47.1% (6,359) and UPF's Harbans Singh's 1.0% (131), marking the first time since 1961 the Anson electorate voted the WP into the assembly.

The prosecution later appealed a retrial to be held in a different district court, which saw Jeyaretnam found guilty on all charges and resulted in his disqualification, though he subsequently remained as the party's Secretary-General, he was also barred from standing in elections until 1991.

[12] In 1987, some members were among a group of 22 people arrested by Singapore's Internal Security Department as part of Operation Spectrum, accused of being Marxists.

A by-election in the Marine Parade Group Representation Constituency in 1992 was expected to mark the return of Jeyaretnam to electoral politics after his Parliamentary ban had expired; however, the team ultimately did not participate due to one of the candidates turned up late on the nomination day.

In 1996, Jeyaretnam was sued and paid damages of S$465,000 and S$250,000 in court costs for an article he wrote in an issue of the party's newspaper, The Hammer, calling the PAP's Indian leaders a bunch of stooges.

Besides Low, only one other opposition MP was elected (Chiam See Tong, who left SDP to join the Singapore People's Party); one NCMP was offered to the WP team for Cheng San Group Representation Constituency, who polled better than any other opposition losing candidates, with 45.2%; the party selected secretary-general (and candidate) Jeyaretnam as the NCMP, marking his return to the Parliament after 11 years.

During the election campaign, another candidate part of the WP's team in Cheng San, lawyer Tang Liang Hong, drew particular attention from the PAP, who accused him of being an anti-Christian and anti-Muslim Chinese chauvinist.

Tang, who insisted all he was trying to do was to "better represent the Chinese community and ask questions on their behalf", vigorously denied this charge and accused the PAP of trying to win votes by sowing fear into the electorate.

Another team of young first-time candidates, led by Yaw Shin Leong in Ang Mo Kio GRC helmed by Prime Minister Lee Hsien Loong, garnered a respectable 33.4% or one-third of the votes, slightly higher than the opposition's national average.

Prior to nomination day (27 April 2011), Low announced that he would vacate his Hougang seat to former Ang Mo Kio GRC candidate Yaw Shin Long, and would contest in Aljunied GRC in the forthcoming election along with Lim and three of his "A-List" candidates (Taiwanese-born corporate lawyer Chen Show Mao, law postgraduate and former SAF major Pritam Singh, and freelance councillor Faisal Manap).

The Hougang ward was also retained by Yaw with its best performance for the party at 64.80% of the votes (second only to Chiam's score of 69.6% back in 1991), resulting in six seats elected in Parliament.

In February 2015, the Auditor-General's Office (AGO) carried out an audit of AHPETC and found several lapses in governance and compliance, which became the subject of parliamentary debate.

All four Sengkang GRC members, as well as Nicole Seah and Kenneth Foo were elected into the CEC, while former MPs Chen, Goh and Lee, as well as Firuz Khan, John Yam and Terence Tan, stepped down.

[67] On 30 November 2021, Sengkang MP Raeesah Khan resigned from the Workers' Party and Parliament after investigations into lying during parliamentary speeches on women's empowerment, which happened three months earlier.

[68][69] Two days later, the Workers' Party Central Executive Committee said they knew about the lies the week after her speech, but they decided to let her set the record straight after knowing her circumstances.

[70][71][72][73][74] Former NCMP Daniel Goh then publicly questioned Khan's resignation on Facebook in several posts and also requested that the party leadership take some responsibility for "allowing the transgression to persist".

[76] On 17 July 2023, a video of MP Leon Perera and the party's youth wing president Nicole Seah behaving intimately in a restaurant surfaced online.

[81] On 7 July 2023, the Supreme Court of Singapore found both Lim and Low, and not Singh, liable for control failures in regards to payment processes in both Aljunied-Hougang and Sengkang Town Councils, leading to a risk of overpayment.

[83] On 22 August, the Ministry of National Development brought considerations for regulatory action pending clarification from AHTC, under witness of its three party leaders, as well as town councillors Chua Zhi Hon, Kenneth Foo, How Weng Fan and Danny Loh, to ensure the safekeeping of the money totaling S$33.7 million in improper payments.

[89] Ahead of the 2025 Singaporean general election, on 7 December 2024, Low Thia Khiang announced that he would retire from politics but would remain a member of the party's central executive committee,[90][91] despite initially expressed interest on his return.

The party also desires increased rights for Singaporean workers and a welfare state, such as allocating greater expenditures towards the country's public healthcare system.