At a press conference on Wednesday to introduce his fellow candidates for Marine Parade GRC, Emeritus Senior Minister Goh Chok Tong urged voters to give the ruling party a "strong mandate".
"If the government doesn't get a good support,"Mr Goh said, "you're repudiating what they have been doing."
He added that it was "very important" that a "clear signal" be sent to the ruling party that voters "liked what they are doing."
Mr Goh, who had Mr Tan Chuan-jin seated beside him, then dismissed the opposition and told voters not to be "distracted" by them.
"Don't chase after bits of meat thrown by the opposition," Mr Goh said, gesticulating with his hands.
"I think that will be a mistake," he added.
Some online have expressed shock at the former prime minister's remarks, which was broadcast on national tv.
Some saw the remarks as likening Singaporeans to animals, or dogs, which they found offensive.
They also found it "extremely disrespectful", and likened it to the 2011 remark by the late Lee Kuan Yew who had told voters in Aljunied GRC that they would need to "repent" if they voted opposition.
Mr Lee's comment, which drew vitriolic reaction against it, was widely seen as having contributed to the PAP's loss of the GRC to the opposition Workers' Party (WP).
At the same press conference on Wednesday, Mr Goh also dismissed suggestions by the opposition that it could act as a check and balance in parliament against the PAP.
Mr Goh said this was a "seductive lie", and that the PAP could check itself.