A switch to electric cars may not necessarily reduce CO2 emissions or dependence on oil, a report for the Environmental Transport Association claims.

It was unlikely that electric vehicles would account for more than 25 per cent of new sales by 2050, it added.

There were significant potential environmental benefits to be had from a switch to electric vehicles, but these were entirely dependent on changes in the way that electricity was generated and energy was taxed.

Under the EU emissions trading system electric cars were likely to result in higher overall CO2 emissions, the report said.