Children wearing face masks and carrying placards joined parents, teachers and residents to protest over foul smells blamed on a Bradford animal rendering plant.
The demonstration, outside P Waddington and Co’s site near the city centre on Tuesday, was the latest by campaigners who say the “gut-wrenching” odours have affected nearby communities for decades.
Among those protesting was Mohammed Daraz, who said: “Every time I’m in the area I find myself having to cover my nose or stop myself from retching. This abomination is dragging down the whole city’s reputation.”
A spokesman for Waddington said the firm respected people’s concerns but had always operated within its environmental permit.
The protest came ahead of a Bradford Council regulatory meeting next month to discuss the factory’s licence.
More than 100 people gathered outside the factory, which turns animal carcasses and roadkill into biofuels, on Tuesday evening.
Protesters’ chants of “end the stink” filled the air, as the factory continued its operations in the background.
Yahya, one of the younger children taking part, said: “When I’m playing outside, I have to go running inside because of the smell.”
His message to the factory and the council was blunt: “Shut this down.”
Other youngsters compared the smell with sewers, raw flesh and rotting food.
Campaigners say the children’s experiences cut to the heart of the issue.
Local businessman and lead campaigner Ummer Daraz said: “The kids, as well as any neighbourhood, deserve clean air, without the fear of being hit by this putrid odour.”
His son Mohammed said the smell had been part of his experience of the area for as long as he could remember.
And he believes the situation is damaging Bradford’s reputation.
“Anyone that comes through this city will assume that this smell is coming from the local takeaways and butchers, but it’s not,” he said.
