The debate on passenger vehicle taxes is taking a close look at fairness at the same time as tackling pollution.
The European Commission is proposing the abolition of national vehicle registration taxes.
These would be replaced by taxes based on levels of carbon dioxide produced by each vehicle.
Part of the reasoning is to avoid situations where people moving to another EU Member State are obliged to pay tax in two countries.
EU parliamentarians working on the subject suggest the tax should be linked to pollution in general and not just CO2.
They have backed the Commission5;s approach, while proposing a broader environmental scope, with the level of tax linked to fuel efficiency and pollutant emissions other than carbon dioxide.