SINGAPORE - Dr Tan Cheng Bock, who lost in the 2011 Presidential Election, said on Friday (March 11) he will make a second bid for the presidency.

The next presidential election must be held by August next year.

"The election is 17 months away. I feel it's now timely to state my decision. I intend and will contest the coming Presidential Election in 2017," Dr Tan, 75, said at a press conference.

The former People's Action Party (PAP) MP for Ayer Rajah from 1980 to 2006 lost the 2011 election to President Tony Tan Keng Yam by 7,382 votes - or 0.35 percentage point - in a four-way contest.

Asked why he is announcing his intention to run for presidency now, Dr Tan said: "I've contested many GEs. I never take my voters for granted... when I contested other elections, I spent years, and 17 months is a good time."

On how he is preparing for the election, he said: "I walk the ground, I go to coffee shops, I attend talks and I give talks."

The press conference was held at the MHC Asia Healthcare in Commonwealth. His wife Cecilia is chairman of the healthcare company.

At the event, Dr Tan outlined his various achievements in his 26 years as an MP: as the first backbencher in years to be elected to the PAP exco in 1987; as an MP who pushed for measures such as the use of Central Provident Fund (CPF) savings for education and free parking on Sundays; as the chairman of the Feedback Unit and the first town council; and as leader of the group of MPs tasked to build links with counterparts in Europe and later South-east Asia.

He also spoke about his experience on various corporate boards and his resignation from the board of the Jurong hospital as he disagreed with its renaming. He was also an adviser to a number of associations and a council member of the Singapore Medical Association.

The announcement comes amid an ongoing review of the elected presidency by a nine-member Constitutional Commission chaired by Chief Justice Sundaresh Menon.

The review will focus on the criteria for who is eligible to stand for the election, provisions to ensure people from Singapore's minority communities have fair and adequate opportunity to be elected president, and refinements to the role and make-up of the Council of Presidential Advisers.

Several of Dr Tan's supporters, in comments on social media, see the review as an attempt to disqualify him from running for president.

Responding to a question from the media on whether the timing of his announcement has to do with the elected presidency review by the Constitutional Commission, Dr Tan said: "That I put aside. Today, I let you know that I want to contest, not that I am pre-empting the commission."

As for whether he has given advice to the Constitutional Commission, he would only say that is between him and the commission.

Dr Tan was also asked for his response if the elected presidency review decides to allow only candidates who are 75 or younger in 2017 to contest in the election. He said: "I am ageing gracefully... I am a doctor and I take care of my health. I mange what I eat and I walk a lot."

On how he intends to play the role of a unifying figure if he is elected, he said he wants to promote multiracialism. "Multiracialism is very important to Singapore, and we have new immigrants, they are an important part of society. We must not take multiracialism for granted, and I want to promote that."

He added: "The President must go into office with the intention of keeping Singapore stable and not to destroy the country."

Dr Tan had hinted at his intention to make a second bid for presidency in a Facebook post on Wednesday (March 9). He wrote then: "At the last Presidential Election in 2011, some 738,000 Singaporeans voted for me. Many of my friends and supporters have asked if I intend to contest in the forthcoming Presidential Election in 2017.

"I owe them an answer. This Friday, I shall let Singaporeans know of my intention," he said.

He has remained in the public eye since 2011 and attended rallies by the PAP as well as several opposition parties during last year's general election.

Some opposition politicians as well as grassroots leaders from his old ward also attended a gathering at his house during Chinese New Year last month.

Political observer Derek da Cunha said on Facebook that the timing of Dr Tan's announcement is probably of significance, taking place amid a review of the presidency.

He wrote: "Will Dr Tan say that he would like to contest the next election as long as he meets the eligibility criteria, and that as he met the criteria back in 2011, that he should be permitted to re-contest in 2017?"

The 2011 election was also contested by Mr Tan Jee Say and Mr Tan Kin Lian. Mr Tan Jee Say said last Saturday that he did not rule out standing in the next presidential election if he qualifies.