Bath motorists may be charged to enter spa city centre
Proposals for a "clean air charge" in Bath have sparked concerns over the impact on tourism.
The local council wants owners of high-emission vehicles, including tourist coaches and HGVs, to pay to enter a central clean air zone (CAZ).
Members of the spa city's tourist trade have pleaded with the authority for a "common sense" approach to the plan.
Bath & North East Somerset Council said it would have a "positive" effect on air quality.
The plan is part of the city's effort to meet government air quality targets by 2021.
It has made up to £3m available for a scheme that will include improving greener modes of public transport.
But the final plans, as well as costs for entering the zone, are yet to be finalised.
Under proposals outlined by the authority, a CAZ will affect an area with a 5m (8km) radius, including some of the city's central Georgian sites and its main shopping routes.
In 2016, tourism contributed more than £430.5m to the local economy and was responsible for 10% of all employment in Banes.
Martin Curtis, of the Bath Bus Company - which runs open top bus tours - said his newer vehicles would not be affected by emissions demands, but their customer base could be.
"Our concern is the effect on Bath's tourism and trade as a whole," he said.
Steve Spiller, director of coach firm Centurion Travel, said he supported a clean air zone but hoped for a common sense approach from the council.
"If the level of emissions regulation is too strict from the offset, it will be impossible for coach companies to replace their vehicles in time," he said.
The company also busses about 600-700 pupils around Bath during term time, Mr Spiller said.
"We currently have six vehicles that meet the highest Euro Six standards, but if the CAZ rules are too severe, they will have to be allocated to the highest paying customers - schools will miss out because they won't be able to pay the higher costs."