A final consultation on making Oxford a Zero Emission Zone (ZEZ) has been launched.
Oxfordshire County Council and Oxford City Council are asking for feedback after a previous consultation was paused due to the Covid-19 pandemic.
Under the plan non-zero emission vehicles using the zones between 07:00 and 19:00 will be subject to charges.
Tom Hayes, the city council's deputy leader, said emissions standards "will be the toughest possible".
A pilot is due to start on Bonn Square, Queen Street, Cornmarket, part of Market Street, Ship Street, St Michael's Street, New Inn Hall Street, and Shoe Lane in the summer, in the so-called "red zone".
A wider ZEZ covering the rest of the city centre will be introduced in spring 2022.
Discounts have been proposed for residents and business vehicles, as well as Blue Badge holders, for the first few years.
Mr Hayes, who is also cabinet member for green transport, said: "The city has joined together in recent years to develop this ZEZ scheme and we hope for the largest number of responses to our final consultation."
Analysis: Bethan Nimmo, BBC Oxford political reporter
This is being billed as the first "true" zero emission zone in the world.
But you will still be able to drive into the zone in a petrol or diesel car - you'll just have to pay for the privilege.
That's led to previous criticisms that it's not really a zero emission zone.
Both councils involved here insist it is, and that it will make a real difference to air quality.
Initially it will only cover a few streets, with plans to roll it out to the rest of the city centre in 2022. There's also an ambition to implement this across the whole of Oxford in 2030.
Taking this scheme together with plans for Low Traffic Neighbourhoods and new bus gates, it's set to get a lot more difficult, and costly, to drive a private car into the city in the next few years.
Yvonne Constance, the county council's cabinet member for the environment, said: "Tackling air pollution and climate change is a great priority for us."
She said people could "look forward to a city that will be a healthier and cleaner place for all".
The responses to the consultation will be reported to the councils' cabinets in March.
Both councils are also preparing a separate business case to make Oxford Britain's "first all-electric bus town" with the Department for Transport.
Prime minister Boris Johnson recently announced that new cars and vans powered wholly by petrol and diesel will not be sold in the UK from 2030.