The City of Cape Town says threats by firefighters to "withdraw" their services over alleged unpaid overtime is part of a "misinformation campaign".
Mayoral committee member for safety and security JP Smith said: "The issue [of firefighters overtime pay] has resurfaced in recent weeks, nearly a year after a similar misinformation campaign by the union, and once again there are threats to 'withdraw' their labour".
On Thursday, firefighters marched in the Cape Town CBD, with the support of the South African Municipal Workers' Union (Samwu).
Samwu's Sebenzile Kiva said firefighters were currently employed to work 40 hours a week but, in most cases, they ended up working anything between 72 to 80 hours a week.
Smith said there was a misrepresentation of firefighters' working hours.
"The current work hours of the fire service are regulated by an agreement to which Samwu is a signatory," he said.
Smith added that the union was not prioritising the interests of firefighters.
"Instead of acting in the interests of their members to resolve the labour dispute, they have opted to draw it out, essentially waging the matter in the media. This is not in the interests of the firefighters."
He then pointed to a 2007 collective agreement which, he said, was signed by Samwu and the Independent Municipal & Allied Trade Union (Imatu).
In it, Smith said, a determination on the working hours of staff was concluded in 2007, with a period of operation until 2010.
In 2010, the City, Imatu and Samwu agreed that the agreement would remain in place until a new one was negotiated.
In reviewing the agreement, the City first offered "to increase the standby allowance to 30%, but this was rejected. Voluntary arbitration saw a 35% allowance offer tabled, which too was turned down".
He added that the current demand "stated through the media would require a R146m additional budget".