Sheffield has opened a consultation on its plans to create a Clean Air Zone (CAZ) in the city.
By 2021, the city council proposes coaches and buses that aren't electric or Euro 6 will be charged £50 for entering the CAZ.
Non-Euro 6 HGVs, vans and taxis will also have to pay a charge.
Private cars will not be charged, although the city council asks: “We need diesel drivers to switch to less polluting vehicles.”
The city council is seeking £50m government funding to support vehicle operators, but this will be “to help those people whose livelihoods depend on a van or a taxi.”