A businessman claims his company will go bankrupt because of a new diesel ban in Bristol.
Richard Martin, from Gas Safe Bristol, has started a Tradesmen Against Diesel Ban campaign on Facebook.
He claimed the plan would cost him £50,000 a year and have "no impact on clean air... because we have no other choice but to operate these vehicles".
Bristol City Council said non-compliant commercial vehicles would be charged for entering the Clean Air Zone.
"Once inside the zone, they can travel freely, including entering the Diesel Ban Zone without being fined," the authority added.
"We will be launching a scrappage scheme for people who want to change to less polluting vehicles."
Two weeks ago, the city became the first in the UK to propose such a ban in a bid to reduce air pollution.
But a campaign page opposing the scheme has gained more than 1,000 followers since it was set up.
Heating engineer Mr Martin, who owns a fleet of 23 diesel vans, also said the scheme would cost his firm tens of thousands of pounds a year.
"If they're talking about somewhere between £5-10 a day to access the areas, most of our vans will travel the length of Bristol every day," he said.
"So it will probably affect every van and it could be up to six days a week and that's working out £50,000 a year and that's us bankrupt."
Angela Smith, who runs a small business in St Philips, said: "I can't afford to buy anything new and I need a van because I have to make deliveries that are not going to fit into a car.
"There are other things that can be done [rather] than having a snap decision."
Details of specifics - such as the cost of fines and who might be exempt from the ban - are yet to be decided by the council.