Minister Vivian Balakrishnan used the phrase "honourable man" twice in the House yesterday to describe not a People's Action Party (PAP) colleague but Workers' Party (WP) chief Low Thia Khiang.
He had far harsher words for WP chairman Sylvia Lim and her fellow Aljunied GRC MP Pritam Singh, who are also chairman and vice-chairman of Aljunied-Hougang-Punggol East Town Council Council (AHPETC) respectively.
The Environment and Water Resources Minister criticised their conduct in a long drawn-out dispute among AHPETC, hawkers and the National Environment Agency (NEA), over the cleaning of food centres in Bedok North.
The hawkers involved said AHPETC property manager Tai Vie Shun demanded extra payment for the cleaning of the food centres' high areas, even though the NEA requires town councils to carry out and pay for such cleaning.
Ms Lim and Mr Singh's public denials of town council wrongdoing were "false and untruthful", Dr Balakrishnan charged yesterday, adding that the real issue was one of "integrity".
The exchange between the minister, Ms Lim and Mr Low took place during Question Time, thanks to a question filed by Ms Lee Bee Wah (Nee Soon GRC).
It lasted just over half an hour, during which Mr Singh said not a word.
The exchange was significant in two ways.
First, it was a display of the PAP going on the attack. That was also in evidence on Monday when Minister for Communications and Information Yaacob Ibrahim took aim at "prominent bloggers" for contributing to confusion during the recent haze crisis.
Yesterday was also not the first time the WP came up against a PAP offensive in Parliament.
Back in May, National Development Minister Khaw Boon Wan came down hard on AHPETC's ties to its managing agent and the fees it paid.
Yet the WP seemed decidedly unprepared yesterday, while the PAP side came all set for a robust exchange.
Dr Balakrishnan not only marshalled arguments but also produced a dossier of documentary evidence against AHPETC.
The Prime Minister, two Deputy Prime Ministers and the Law and Foreign Minister were also present, listening intently to the exchange.
Throughout, the WP remained on the defensive, lacking fresh arguments to rebut the PAP charges.
Ms Lim and Mr Low's main defence was that it was all a misunderstanding between the town council, hawkers and NEA over quarterly spring cleaning versus annual cleaning.
Town councils are required to clean food centres' high areas only during the latter.
Ms Lim stuck to her guns, saying "it is still the consistent position of our town council that Mr Tai at no time said that the hawkers had to pay extra to fulfil the town council's annual obligation to clean the high areas.
"At no time was this said, I don't think these documents show it either," she said, of the Government's dossier.
The minister, though, would have none of that. Whatever the case, the crux of the issue was that the WP's official had sought higher payments from hawkers, contrary to what the two MPs had asserted, he insisted.
Yesterday's exchange was also significant for the way Dr Balakrishnan attempted to divide and conquer - by casting Mr Low as an honourable politician who does right by those he represents, including hawkers; and contrasting that with the approach of Ms Lim and Mr Singh, whose integrity he called into question repeatedly.
He pressed his point, with some no-holds-barred rhetoric: "Politics is a contest for power. But you know, the key principle when you have power is - don't take advantage of people under your charge, and always be honest and upfront with your people... When a mistake is made, just come clean and say so. But don't cover up. That's why I have not let this go. Because it is not about cleanliness of the ceiling, it is about clean politics."
Turning to Mr Low, he added: "I appeal to you, because I know you to be an honourable man, I appeal to you, go back, do a thorough investigation of what's gone on and what's gone wrong in your town council and put it right."
Whether Mr Low takes up his suggestion remains to be seen. There was no word from him on this last night. But given the WP's internal discipline, its leaders may well close ranks under fire from the PAP, which could also win it some sympathy. Personal attacks on opposition politicians have rarely gone down well with the Singaporean public.
How the public responds will also depend on whether they buy the minister's argument that at the crux of the whole sorry episode is a question of "clean politics" and integrity.