A convoy of Blacktown garbage trucks lined up outside SBS headquarters in Artarmon on Wednesday as Blacktown City Council mayor Stephen Balisaid the broadcaster's integrity was "on the line" over Struggle Street, set primarily in the suburb of Mount Druitt.

In a letter to Cr Bali seen by Fairfax Media, SBS said it had investigated all the allegations made by the council and rejected all of them.

"We are confident that Struggle Street is a fair and accurate portrayal of events that occurred during filming," said Helen Kellie​, the network's chief content officer. "Further, we believe the series fairly reflects the program description contained in participant release forms."

Cr Bali accused SBS and production company KEO Films Australia of treating participants unfairly and portraying Mount Druitt in a negative light, saying the program was "not a documentary" but "publicly-funded poverty porn".

He suggested the program had been edited unfairly and some scenes had been "engineered". For example, the first episode appears to show two men purchasing snacks with income they earned from scrap metal, rather than buying food for their families – but Cr Bali claimed the snacks had actually been paid for by producers.

"They're not raw scenes of how people act their lives out," he said outside SBS on Wednesday. "The program is garbage so we brought garbage trucks here."

Ms Kellie acknowledged that in the process of filming, crew members had sometimes provided the documentary's subjects with "light refreshments" as a courtesy, and with mobile phone credit so they could stay in contact with crew. But she denied these were "inducements", as had been claimed by Cr Bali. Participants were not paid for the program.

Speaking to media on Wednesday, Ms Kellie said Struggle Street was a "raw [but] fair reflection" of the six months crew had spent with the families.

"This is not a sugar-coated version of people's lives," she said. "These are people who are living with real disadvantage."

The broadcaster has been under attack over Struggle Street since it aired a trailer depicting one of the documentary's subjects, Ashley Kennedy, breaking wind on his front porch, a woman calling her cat a "slut" and another woman smoking what appeared to be marijuana.

The first full episode of the series – scheduled to air on Wednesday night and seen in advance by Fairfax Media – explores several issues faced by socio-economically disadvantaged residents in Mount Druitt, including homelessness, drug use, disability and teen pregnancy.

Among the Kennedy family's struggles are a husband with health problems and recently-diagnosed dementia, a son addicted to ice, another son with brain damage from an accident, eight other children and no employment.

Mr Kennedy's wife Peta told Fairfax Media she was "very shocked, very gutted and very hurt" when she first saw the documentary's trailer. The 54-year-old from Willmot, near Mount Druitt, said her husband was diagnosed with dementia during the six months of filming, and that the trailer had led to her 19-year-old disabled daughter being identified and bullied.

"I hate being called a houso, I hate being called a bogan, and I will not stand for my family being attacked," she said.

Mrs Kennedy said that although the first episode of the three-part series was fairer than the trailer, it was still problematic and deeply personal.

"There's some good stuff and there's some raw stuff," she said. "Some parts didn't need to be in there."

Cr Bali said Struggle Street was not just an unfair portrayal of Mount Druitt and western Sydney, but an attack on Australia's working class. He said the issue "has united the whole of Sydney" and that the garbage trucks had received hundreds of toots of support on their pilgrimage from Mount Druitt to Artarmon.

Individual subjects of the program were expected to seek legal advice following the broadcast. Lawyer George Newhouse​ told the Guardian Australia he was investigating the possibility of legal action, including defamation suits, on behalf of some residents.

It is not the first SBS program to attract controversy; the comedy Housos poked fun at families living in housing commission estates, while documentary Go Back To Where You Came From explored Australians' attitudes towards refugees.