Deputy Prime Minister Teo Chee Hean said Singaporeans may end up paying "quite a high premium" if they vote for the opposition, and should instead continue to support the ruling party.
Mr Teo was speaking during the unveiling of the party's sixth batch of candidates on Thursday afternoon. In his speech, he also said that voters may find that when they try to cash in the policy, the opposition "can't deliver".
"By the opposition's own admission, if you ask them, are you ready to form a government…they say, no, no, we're not ready.
"So what they're actually asking you to do is to pay a very high premium for a so-called insurance, which…they can't deliver," said Mr Teo, who is also the Minister for Defence.
On the other hand, the ruling People's Action Party (PAP), he said, is the "real insurance policy" that Singaporeans should buy to continue having a good, strong government, reported The Straits Times.
The insurance argument was first brought up by the Workers' Party when it called on the electorate to ensure that the opposition would have a strong enough presence in parliament to provide a safeguard for the public in case the PAP falters.
At a forum at the National University of Singapore on Tuesday, Prime Minister Lee Hsien Loong had countered this argument, saying that the way to protect Singapore's future was to give unwavering support to PAP's team of candidates, rather than to weaken that support by favouring the opposition "in the hope of buying insurance".
Minister Teo supported PM Lee's point and called on voters to support the ruling party's candidates. Although the new faces may not be fully experienced today, they will learn the ropes and be "in a good position to take the country forward into the next decades", he said.
Regarding the argument of the Workers' Party, he cited the example of Belgium, which has been unable to form a government since its last general election in June last year.
"Now, it's not for lack of political parties. They have many political parties. Using the opposition terminology, many insurance policies. But the insurance policies don't work. So they haven't been able to form a government," he said.
The minister also said that he welcomed the scrutiny of the new candidates and hoped that there would be equal scrutiny of opposition candidates. At the same time, critics, he said, should be upfront and not hide behind cloaks of anonymity.
"Criticism which is based on untruth and particularly by anonymous people is not good for our system and can be destructive," he said.
Responding to statements by some opposition candidates who said that they would become full-time MPs if they were voted in, Mr Teo said being full-time was no guarantee that they would be able to run town councils well.
What was more important, he said, was the ability of the MP to bring in a good team of people to run the town council.