Paul Harris, Liberal Democrat spokesperson on green issues said:
"These proposals are a dramatic change of position by the City Council. The proposal for emission charging represents the adoption of an idea for which Liberal Democrats have been calling for a long time. Discouraging non-electric vehicles from entering the city by a charging system is obviously a more sensible overall approach to the problem and ties in with the need to find much needed funds for adequate public transport.
"Regrettably there are still major problems with the latest proposals.
"The Council proposes a Red Zone introduced this year in just 6 streets, and a larger Green Zone in 2021/22. The Red Zone will make no difference to air quality or congestion as the streets affected have little traffic. The Green Zone however will make a substantial difference. Implementing the Green Zone in a fair and effective manner will be a challenging task. We believe that the 2020 Red Zone is pointless, and that all efforts should go into preparing for charging in the Green Zone.
"We are also concerned about the application of the charge to delivery vehicles at a time when many city centre shops are under severe economic pressure.
"We will be preparing a detailed response to the consultation and hope that the City and County Councils will both be in listening mode."
The latest proposals can be read in full on the Oxford City Council website.