Lost Business for firms in the city centre. It is argued that a congestion charge will encourage people to visit out of town shopping centres and lead to a decline in city centres.
Expensive to Administer. The costs of collection a congestion charge is much higher than petrol tax. It requires sophisticated technology and chasing up drivers who don’t pay or try to avoid. For smaller cities the administration costs may be prohibitive.
Evasion. Since the congestion charge has been introduced, there has been a growth in the number of false number plates and schemes to try to avoid paying the tax (such as setting up false mini cab firms)
Inequality. A congestion charge is regressive as it takes a higher % of income in tax from the poor.