Bristol is set to become the UK's first city to ban diesel cars from entering parts of the city centre in a bid to cut air pollution.
Bristol City Council has agreed to ban privately owned diesel cars from a central zone in the daytime. Commercial vehicles will pay to enter the area.
The city has long suffered from poor air quality, particularly from high levels of nitrogen dioxide (NO2).
The scheme, which needs government approval, is due to start in 2021.
Which areas will it cover?
The central ban zone, where privately owned diesel cars will be banned between 07:00 and 15:00, includes part of the M32, the old city, Redcliffe, Spike Island, the Harbourside, and part of Hotwells.
Vehicles, with the exception of taxis and emergency services, will incur fines if they stray into the area.
A wider Clean Air Zone (CAZ) extends further away from the city centre.
Which vehicles will it affect?
Diesel powered lorries, vans, buses and taxis which pay to enter the wider clean air zone will also be allowed in the central zone.
Taxis and vans will pay a daily charge of £9 and buses and HGVs £100.
Private diesel cars will not be charged to enter the wider clean air zone.
How will it be enforced?
A number plate recognition system, similar to the one used to police London's congestion charge will be used.
The city council has agreed a business proposal for the idea, but details of specifics such as how much fines will be, and which categories of vehicles and people might be exempt from the ban, are yet to be decided.
Why is it happening in Bristol?
Bristol City Council is under a legal obligation to reduce air pollution in the city by lowering toxic NO2 levels to within legal limits as quickly as possible.
However the city has twice missed government deadlines for providing details of a clean air zone.
It is hoped this new plan will enable it to achieve clean air compliance by 2025.
Pete Simson, BBC Radio Bristol politics reporter, said: "It's hard to overstate how significant a policy intervention this is.
"This is a first, no other UK city is introducing an outright diesel ban, and it will require the government to introduce new legislation."
How is the issue being tackled in other cities?
Low emissions zones have already been debated in several other UK cities, including Birmingham, London and Leicester.
Many of these schemes involve older, more polluting diesel vehicles being banned from certain areas or vehicles having to pay to enter zones.
Similar systems exist in many European cities. In Oslo a total diesel ban can be enforced on the most polluted days.
What do people set to be affected by the ban think?
While some local people have welcomed the idea, others say the plans are too complicated and fear it will simply move the most polluted area away from the city centre.
There are also concerns the scheme will hit low-income families the hardest.
Alan Peters from bus company Abus which operates services around the city, said penalising buses was "excessive and the wrong approach".
"They should be encouraging the use of buses rather than increasing the cost."
He said it would need £1.25m of investment to replace his vehicles on the route between the city centre and Keynsham.