Drivers of diesel-run cars may soon face higher motoring charges under new plans to fight pollution.
They could be saddled with a road tax rise or extra charges to drive through city centres, according to a report in The Times.
Boris Johnson, the London mayor, is considering a £10 levy - in addition to the existing congestion charge - for nearly every diesel vehicle travelling into the centre of the capital.
The only exemptions would be diesel cars hitting the stipulated Euro 6 discharge standard. In addition, petrol-run vehicles registered prior to 2006 would be subject to the charge.
Mr Johnson also wants ministers to raise diesel vehicle road duty.
RAC Foundation director Professor Stephen Glaister said: "This isn't quite a mis-selling scandal, but for years ministers took their eye off the ball and encouraged drivers to buy diesels to help fight climate change.
"That has come at a cost: local air pollution. Today 10 million cars in Britain are powered by diesel engines - a third of the total.
"Part of the problem is regulation. In laboratory conditions diesel cars have met strict test criteria. Unfortunately that performance hasn't been matched on the road and now we have a significant health issue because of the dash for diesel."
Leading UK cities are already considering whether to follow London's lead and introduce low-emission areas to deter older diesel cars which generate greater quantities of fumes, the newspaper reports.
Birmingham, Oxford, Bristol and Sheffield are among the 15-plus cities looking at Labour's reported plans to launch a nationwide low-emission network.
This is in a bid to force out older diesel vehicles and encourage drivers to consider cleaner cars.
Copyright Press Association 2014