In the 2015 General Election, Mr Charles Chong wrested back the Workers' Party-controlled Punggol East constituency by a thin margin.

Yesterday, his campaign team disclosed for the first time his winning formula.

One key message projected during the closely-fought race was Mr Chong's record of being his own man: a People's Action Party MP who would lobby publicly against government positions that he disagreed with.

His independence of mind was highlighted while his maturity and experience vis-a-vis his opponent's youth was played down at the hustings, said Mr Chong's legislative assistant Daniel Tan at the Asian Conference for Political Communication.

The strategy, his campaign team believed, would appeal to the younger voters in the single-seat constituency.

"We relied on gut feel and asked ourselves what sort of messaging would resonate with the young," added Mr Tan, 40.

Punggol East has a disproportionate number of young couples, with two-thirds of voters below age 50.

Mr Tan, a lawyer and Mr Chong's legislative assistant since 2002, was speaking at a session on election campaigns.

He said that at the hustings, the fliers distributed and conversations with residents drew attention to instances when Mr Chong disagreed with the Government.

One well-remembered episode was in August 2005, when he and some grassroots leaders put up white elephant placards outside the completed Buangkok MRT station. It was to lobby against the Government's decision to keep the station unopened until there are enough households in a 400m radius to support the capacity.

The station was opened in January 2006.

Another was in 2014, when he helped persuade the Government not to means-test Singaporeans for the Pioneer Generation Package.

Mr Chong, the Acting Speaker of Parliament, has been a PAP MP since 1988.

Over the years, he gained a reputation for winning tough seats.

The Punggol East seat had been won by WP's Lee Li Lian in a 2013 by-election. But in the 2015 General Election, Mr Chong took it back for the PAP, with 51.8 per cent of the votes against Ms Lee's 48.2 per cent.

Before winning in Punggol East, he fought another close battle in the 2011 General Election, when he defeated WP in single-seat Joo Chiat, with just 51 per cent against WP's 49 per cent.

On the night of the 2015 election results, Prime Minister Lee Hsien Loong lauded Mr Chong and other PAP candidates who stood in WP-held wards, saying: "They showed that the PAP has fight, that no opposition constituency can consider itself 'safe'."

When campaigning in Punggol East, Mr Chong's team took great pains not to overemphasise his "years of experience against a much younger, first-term MP", said Mr Tan. Mr Chong was then 62 and Ms Lee, 37.

"We wanted to make sure his age was not seen as a disadvantage and that he was not exploiting his experience over a relatively inexperienced candidate," he added.

Also, printed fliers and posters were designed with graphics that had the look and feel of an online poster. For example, icons were used liberally.

"We felt the younger voters would be more familiar with the online user experience and therefore be more receptive to the messaging," he said.