After months of speculation, Speaker of Parliament Halimah Yacob broke her silence yesterday on whether she would run for president, saying: "I am thinking about it."

While she stressed after a Marsiling community event that she was "not really announcing" a bid, her comments to reporters now put her at the head of the queue in the run-up to the September election reserved for Malay candidates.

She will be considered the front runner, given her high public profile, and political observers said her decision to address an issue she had previously been coy about will give sharper focus to potential candidates and the upcoming election.

Madam Halimah, 62, ticks all the criteria boxes for candidates from the public sector, having served at least three years in a key public office - that of Speaker since 2013.

So far, two others - businessmen Mohamed Salleh Marican, 67, and Farid Khan, 62 - have declared their intentions to contest.

The election is significant as it is the first reserved election following changes to the elected presidency scheme last year to ensure that the highest office in the land reflects the multiracial society here. Singapore has not had a Malay president since Mr Yusof Ishak.

Still, Madam Halimah remained cautious, saying when asked that there was a lot to consider and family to consult: "That's why I want to share with you the thought processes that I go through... before making the final decision."

She added that residents in her Marsiling ward and Singaporeans from all walks of life have asked her if she was likely to contest.

"I am really deeply honoured and also deeply humbled," she said. "The elected presidency is a very heavy responsibility and a very important institution in Singapore, so it is not something that one should take lightly... It is not an easy decision to make."