Adrian Tan Cheng Bock (Chinese: 陈清木; pinyin: Chén Qīngmù; born 26 April 1940) is a Singaporean politician and medical doctor. A former member of the governing People's Action Party (PAP), he was the Member of Parliament (MP) for Ayer Rajah SMC between 1980 and 2006. After leaving the PAP, Tan founded the Progress Singapore Party (PSP), serving as secretary-general between 2019 and 2021 and as chairman since 2021.
 Tan was born on 26 April 1940 in Singapore. He came from a Hokkien-speaking family.
 Tan attended Radin Mas Primary School and Raffles Institution (RI).  He graduated from the University of Singapore in 1968 with a Bachelor of Medicine and Surgery.
 Tan has been the medical director of Ama Keng Medical Clinic in Jurong since 1971. He has served as the Chairman of the Society of Private Practice, as a Council Member of the College of General Practitioners, as Committee Member on the Council of the Singapore Medical Association (SMA), as Chairman of the SMA Trust Fund, as board member of SMA's Ethics Committee, as SMA's Representative on the Ministry of Health's Committee on the Regulation of Medical Clinics, and as a part-time clinical teacher in general practice at the National University of Singapore.
 Tan entered politics during the 1980 general election under the People's Action Party's banner, and became the Member of Parliament-elect for the Ayer Rajah SMC with a vote of 83%. Tan's subsequent election results with an average of 77% was perceived as one of the best-performing candidates in Singapore, with his best-ever score being his last election in 2001, with 88%.
 While in Parliament, he served as the Chairman of the Government Parliamentary Committees (GPCs) for Education (1987–90), National Development (1991–95) and the Environment (1995–97), and was the Co-ordinating Chairman for all GPCs between 1987 and 1988. He was also a member of the GPCs for Communications (1997–2000) and Defence and Foreign Affairs (2001–06). Tan was the Leader of the Singapore-European Parliamentary Group between 1991 and 1996 and Singapore-SEA Parliamentary Group between 1997 and 2006. From 1987 to 1996, he was an elected member of the PAP Central Executive Committee, the highest ruling committee within the PAP. Tan stepped down as a Member of Parliament at the 2006 general election. He also served as Chairman of the Jurong East Town Council from 1989 to 1991, Chairman of the West Coast–Ayer Rajah Town Council from 2001 to 2004, Chairman of the Bukit Timah Community Development Council from 1997 to 2000, and Chairman of the Feedback Unit at the Ministry of Community Development from 1985 to 1989.
 He left politics ahead of the 2006 general election, while his constituency was redrawn to the nearby West Coast GRC (Ayer Rajah division has since held by S Iswaran (which was absorbed alongside Iswaran's West Coast), and later Foo Mee Har since the 2011 general election).
 In 1988, Tan, as GPC Chairman for Education, led a team of MPs to argue for the use of the Central Provident Fund (CPF) for education, as an appreciable number of able students were not able to enter local universities due to limited places. Tan felt that education was a form of investment and that all his GPC was asking for was an extra option for CPF members, to let them decide whether to put their investible savings in stocks and shares or in education. Chief argument against the idea was that the use of such retirement savings may leave the account holder with an insufficient amount at the end of his or her working life. Minister for Labour Lee Yock Suan said that there were alternatives available such as soft loan schemes which were interest-free. In answer to Tan's claim that Lee had not clearly stated his position on the issue despite the idea being first mentioned years ago, Lee insisted that his position had always been plain, that he "was against it, but you have pressed me to study it and I shall". The set of guidelines on the use of CPF for Education proposed by the GPC was eventually implemented, paving the way for the beginnings of a wave of Singaporean students studying at local tertiary institutions.
 Tan also convinced the Ministry of National Development (MND) to allow Singaporeans to park their cars for free in Housing & Development Board (HDB) estates on Sundays and public holidays, to promote family togetherness.
 In early 2010, Tan volunteered himself to help residents in Sentosa Cove to meet with Sentosa Development Corporation (SDC) to seek a waiver of the gantry entry charge (S$2 to S$7 depending on the entry time) for visitors to their residences to the Sentosa island. His efforts, however, did not bear immediate fruits. Later in October 2010, the SDC offered to cap the entry charge at a concession rate of S$3.
 Tan actually voted against his own party despite the Whip not having been lifted regarding the NMP scheme, on the grounds that MPs had to be elected by the people and be accountable to an electorate for their views. He received a warning for his action.[citation needed]
 In 1999, when Singapore was recovering from the 1997 Asian financial crisis, and experiencing labour talent shortages in several key sectors, the PAP pushed for a stronger intake of foreign talent to fill the ranks. Although not against this rationale, Tan argued that the Singapore government should tone down its calls for the recruitment of foreign talent and reassure Singaporeans that they came first, which earned him strong rebuttals, including one from George Yeo and a stern rebuke from Lee Kuan Yew.
 In 1985, he made a speech in Parliament about "no more blank cheque" for the ruling party which he revisited on his blog in May 2011.
 After the 2011 general elections, Tan said in a speech at the 52nd Singapore Medical Association Annual Dinner that he had given advice to opposition candidates, including Tan Jee Say, on how to campaign in the elections when they approached him.
 In May 2011, he resigned from the PAP to stand as a candidate in the 2011 presidential election.
 In 2018, Tan led a gathering along with seven opposition parties (Singapore Democratic Party, Reform Party, Singaporeans First, People's Power Party, Democratic Progressive Party, National Solidarity Party, and a new party formed by former NSP chief Lim Tean, Peoples Voice) to plan a possible coalition for the upcoming election.
 On 19 January 2019, Tan filed an application to form a new political party called the Progress Singapore Party, alongside 12 other applicants, to be an "added voice in parliament".
 Progress Singapore Party was officially launched on 3 August 2019. This launch was covered by mainstream local and foreign media, including alternative media. The official launch was broadcast live to the public at 1.30pm. Tan asked Singaporeans, PRs and New Singapore Citizens to step forward together to join the Party as members or volunteers to help bring Singapore to the next level so that the younger generation will have a better Singapore.
 He served as the 1st and founding Secretary-General of PSP from its formation in March 2019 to March 2021. He is the founder and member of PSP group.
 Tan contested at West Coast GRC in the 2020 Singaporean general election which contained his former ward of Ayer Rajah. His PSP team at West Coast narrowly lost again to the incumbent People's Action Party with 48.31% of the vote.
 Tan's appointment as non-executive chairman of Chuan Hup Holdings (CHH) Ltd in 1991 was unusual at the time, as Members of Parliament did not normally hold such positions. Prime Minister Goh Chok Tong, who had been a classmate of Tan's in Raffles Institution, later said that he had initially been inclined to say no to Tan's request because Tan was a medical practitioner with no experience in shipping.
 Goh ultimately agreed to the appointment, but in the letter he sent to Tan made clear his reservations: Goh later confirmed that neither Tan nor his company had ever tried to take advantage of his position.
 Tan has is Chairman of Dredging International Asia Pacific Pte Ltd, a position he held since 1997.
 His past corporate appointments include
 
On 27 May 2011, 20 days after the recent general election, Tan was the first candidate to seek candidacy for the forthcoming Presidential Election; he resigned from PAP earlier that month prior to the announcement (per the constitution, candidates running for the presidential election must be a nonpartisan, independent candidate, and should not affiliate or to represent to any political party). On 22 July 2011, Tan submitted the presidency forms.
 Ahead of the nomination day (due to be held on 17 August), despite anticipation for a strong contest against the other potential rivals who also announced their candidacy (former Deputy Prime Minister Tony Tan, and NTUC Income Chief Executive Officer Tan Kin Lian), he filed his applications on 22 July, and on 11 August, was one of the four candidates (the aforementioned three, plus former Singapore Democratic Party candidate Tan Jee Say) to be granted the Certificate of Eligibility, an item required to complete their nominations during Nomination Day. The four-cornered fight marked only the second presidential election in history (the first was in 1993) with a contest, as the two preceding presidential elections (1999 and 2005) were both uncontested walkovers.
 Tan stated that he would promote multiracialism, if elected.
 
Controversy erupted shortly after Tan declared his interest in the presidency. It was revealed that in a Straits Times article dated back in 1987, Tan had spoken regarding the Singaporean government's controversial Operation Spectrum while he was in Parliament, which saw 22 young Roman Catholic church and social activists and professionals detained without trial. He addressed, in his capacity as Feedback Unit chief, that most Singaporeans had accepted the reasons of the government and the Internal Security Department for the detention. He also reported that certain "solid citizens" were sceptical of the detention. On 4 June 2011, Tan's Facebook administrator cited that as posts on his page about the incident were running contrary to what law courts have ruled, the risk of being sued for defamation was open to both hosts of the site and people behind the posts alike, as such, "(they) are obliged to remove posts that run contrary to what the law courts have ruled." In the presidential candidate broadcast, Tan said, "The President must be above politics" and that "he must not be a proxy to be any political party", as "his interest must be national, not with a political agenda in mind".
 He also proposed that the government and the Prime Minister's Office be separated as "this familiarity attracts unwanted suspicion of undue influence". He emphasised that the separation is a symbolic move required to reassure the people that they are independent of each other.
 Tan also proposed an Annual Statement for greater transparency for Singaporeans to better understand the president's activities and ideas in unifying Singapore. The statement also touches on Singapore's reserves and the rationale behind the appointment or vetoing of civil servants.
 
Tan's campaign slogan was "Think Singaporeans First", a reference to his 1999 debate on the need to prioritise Singaporeans first when faced with prevailing foreign talent policy. 
Tan's selected the palm tree as his symbol, explaining that "The leaves of the palm represents our multiracial society, the trunk represents them coming together, and the roots represents us taking root in Singapore."  On 27 August, Singapore went to choose their seventh and newly elected candidate. About five hours after polls closed, at 1.23am, Tan called Election Department for an Election recount; due to a narrow margin with less than 2% between the top two highest candidates (the other was Tony Tan), ELD approved Tan's request, and vote counting went on for around three hours before the results were finalised.
 At 4.10am, the final results saw Tan Cheng Bock losing the election marginally to Tony Tan by a 0.35% margin (7,269 votes); Cheng Bock garnered 737,128 (34.85% out of the 2,115,118 valid) votes, while Tony garnered 744,397 votes (35.20%).
 Tan requested a second counting of votes and accepted the results and tried to stand again for 2017 Singaporean presidential election. However, changes made to the criteria of candidates rendered him ineligible. In a congratulatory Facebook post published on 13 September 2017, Tan said that the elected Halimah Yacob would assume  "...the most controversial presidency in the history of Singapore."
 In March 2016, Tan declared his intention to run again for president in the next election, which had to be held within the next 17 months.
 In September 2016, the eligibility criteria for the elected presidency was revised to include the "reserved election" (an election made exclusive for one particular race; in the case, Malay candidates), and were passed by the Constitution in November 2016, eventually preventing Tan from running in the election.
 In May 2017, three months before the elections, Tan filed a constitutional challenge to the High Court, to determine whether it is correct to set the election as a reserved election under the newly introduced amendments to the Elected Presidency, and whether Wee Kim Wee (the fourth Singapore's president) is counted as one six-year term since the constitution for the elected presidency was instated in 1991, but the High Court's Justice Quentin Loh dismissed his challenge, providing an explanation that "Article 164(1)(a) provides for Parliament to specify the first term of office of the President to be counted under Art 19B(1)" ("First Term"). Tan later appealed to the Court on 31 July, but the court of the five judges unanimously dismissed his appeal on 23 August, ruling that the Parliament has their full discretion to set the First Term, which President Wee was counted as one term of Presidency.
 The election ended with a walkover after former Parliamentary Speaker Halimah Yacob became the sole candidate to be granted the Certificate of Eligibility, and was inaugurated on 14 September. After the nomination day, he, along with potential candidates such as Farid Khan and Salleh Marican, also congratulated Halimah on her victory.
 Tan has been involved in Charity Organisations such as the Tsao Organisation (2000–2009), Centre for Third Age Ltd (2007–2011), Disabled People's Association (1985–2006), Handicap Welfare Association (1986–2006) and the Credit Counselling Singapore (2002–2007).[citation needed]. In January 2012, he sang in the Meet The Entrepreneur Charity Concert together with 40 other Singapore entrepreneurs like Andrew Chow to say that "If you ever change your mind, come back to me in 2016, I will be back to fight again, please understand".
 Tan is married to Cecilia Lee Choon Lian and they have one son and one daughter together.
 Tan has been awarded numerous accolades from various organisations.[citation needed]