A vote for the People's Action Party (PAP) is a vote for certainty, said its Bukit Batok by-election candidate Murali Pillai.
The party has helped to set up various social programmes in Bukit Batok in the past 40 years, Mr Murali noted in his second and final rally.
The constituency would also remain with the Jurong-Clementi Town Council, which has the capability, resources and a good track record, he added.
"A vote for us means a vote for certainty - there's no need to experiment," he said.
And progress cannot be taken for granted, or "we will slip back very quickly in this highly globalised and competitive world".
Mr Murali cited the late Bukit Batok MP Ong Chit Chung, a military historian, who recounted how Singapore was seen as an impregnable fortress before World War II. Yet it fell because the British "took their eye off the ball".
"To continue to survive, we need to keep our eye on the ball. We need to always think of your needs, your concerns, making sure our programmes are effective, making sure we have more programmes to suit your needs," he said, urging voters to give him a strong mandate on May 7.
Giving what Deputy Prime Minister Tharman Shanmugaratnam described as his loudest speech, Mr Murali also tackled the criticism of his Singapore Democratic Party (SDP) rival Chee Soon Juan, who said he would not be an effective MP.
"I will not be muzzled," he said, adding that he would push to tighten the criteria for employment passes and get higher ElderShield insurance payouts for the disabled, among others.
Party colleagues vouched for Mr Murali's character.
Minister Chan Chun Sing rebutted SDP's claims that Mr Murali would be just another PAP voice. He said that in their dealings, "when he didn't agree with me, he will tell it to my face".
Mr Chan added: "He has guts."
South West District Mayor Low Yen Ling, referring to Mr Murali by his nickname, said: "Look around the world. In such a time, it is steadiness, consistency and faithfulness that you need... Ah Mu will be like a steady rock."
Jurong GRC MP Ang Wei Neng said that when SDP won Bukit Gombak and Nee Soon Central in 1991, the town councils ran a deficit. Both Dr Chee and his wife worked for the councils, he said.
Fellow GRC MP Rahayu Mahzam referred to Dr Chee's slogan "Now is the time" and said: "This is the time for you to decide, but this is not the time for you to take a chance on your future."
DPM Tharman said of Mr Murali: "He dares, he delivers, he works out solutions and you will always know he's doing it because of you, not him. You can trust Murali to build a team, strengthen a team, build new leaders, and keep it going... It requires persuasion, it requires people feeling that you're with them, it requires credibility, and this man has it."