SINGAPORE - The results of the elections show a "significant reversal" in support for the Workers' Party, and the key reason is that voters cannot be hoodwinked, said Law and Foreign Minister K Shanmugam on Saturday.

The WP lost the Punggol East seat to the PAP and retained Aljunied GRC and Hougang SMC, but with slimmer margins than before.

"The voteslide across the board in all the constituencies they contested, hitting 30-odd per cent when they used to hit 40 odd, is a significant reversal, and I think there are clear reasons for that," said Mr Shanmugam.

Speaking to reporters ahead of a Thank You parade in Nee Soon GRC, which his PAP team retained with 66.83 per cent of the votes against a WP challenge, Mr Shanmugam said:

"I think the clue is in what Ms Lee Li Lian (the WP's losing Punggol East candidate) said last night: municipal issues. The Singapore public, they are very discerning. You can't hoodwink them. You can't leave a lot of questions unanswered on the table and go to rallies and say, I have answered all the questions."

"You try that, they will punish you. I think in the voting booth, they went in and thought to themselves, there are lots of questions here that have not answered. And why are they not answering?"

Mr Shanmugam was referring to questions about how the WP-run Aljunied-Hougang-Punggol East Town Council has managed residents' funds.

"So many unanswered questions relating to millions of dollars, and a refusal to answer in Parliament, and statements from the High Court which are highly critical. These are all in people's minds," he said.

"People won't know details, they won't know ins and outs, they won't know balance sheets. But they know something is wrong. Not just that something is wrong, they also know that there is constant evasion."

"And you can't take people for granted. The PAP cannot, and the opposition cannot."

He said that the election results are a "vindication" of the approach that the PAP has adopted in politics, which is to make character, integrity and honesty the fundamental qualities that politicians in Singapore must have.

"If we want a good system, then you need the population to say I'm going to vote for people of character, integrity and honesty. Second question is then which party does he belong to?"

The PAP's landslide would not be taken for granted by the ruling party, he added; the strong mandate would be taken as impetus to work harder.

"Because our electorate is savvy, sophisticated. You do wrong things, you will get punished."

"People know that the PAP will keep on its toes, will be accountable and if it doesn't do either, it can be delivered a very sharp lesson."