The dispute over the cleaning of a Bedok hawker centre was caused by an e-mail sent by the National Environment Agency (NEA), Workers' Party (WP) chairman Sylvia Lim said on Sunday.
In a media statement, she also made public the contents of the correspondence which triggered the saga.
In it, an NEA staff member had written to the WP-run Aljunied-Hougang-Punggol East Town Council (AHPETC) on Feb 7 regarding the cleaning of Block 538 in Bedok.
She wrote: "Pl note that the Hawkers Association will make the necessary arrangements with their contractors on the scaffold erection/dismantling during the spring cleaning period from March 4-8."
The hawker centre ceilings were eventually not cleaned as there was no scaffolding, leaving Block 538 hawkers unhappy. They also complained that the town council told them they would have to pay extra for scaffolding to be erected for scheduled clean-ups, though they never had to previously.
After the dispute was reported in the media a fortnight ago, the NEA said that the Feb 7 e-mail referred to scaffolding to put canvas covers on stalls, and not for cleaning ceilings which the town council is responsible for.
But in her statement yesterday, Ms Lim said of the Feb 7 e-mail: "NEA had confirmed that the hawkers' association would be providing the scaffolding which was not done for reasons unknown to us."
The NEA was "contradicting itself", she added.
She went on to say that the agency has yet to clarify if the Bedok hawkers were asked by the town council to pay extra for cleaning services, a key sticking point in the dispute.
All the government agency had was a quotation from a cleaning contractor addressed to the market association of Block 538, she added.
The NEA should know that the cleaning contractor, ATL Maintenance, is an independent commercial company "free to provide quotations" to any party that requests for one, Ms Lim said.
It was the market association who had asked for a quotation, she insisted. But the hawkers claim the quotation was unsolicited.