An electric car plugged into a charging station in front of the German utility E.ON's headquarters in Essen. File photo: Wolfgang Rattay / Reuters

Berlin, Germany - Subsidies to help persuade Germans to buy electric vehicles have helped boost demand but cannot go on forever, Chancellor Angela Merkel said on Thursday.

Germany wants to increase electric car sales, especially in the wake of a diesel emissions cheating scandal that has engulfed the auto industry in the last three years. A  1 billion (R16.5 billion) subsidy scheme helped more than double sales in 2017.

"Now there is talk about extending incentives. But this cannot be a permanent subsidy," Merkel told an e-mobility event, reiterating that Germany would miss its target of having a million electric vehicles on the road by 2020 by two years.

She also repeated her call for European countries to develop battery cells. Currently the industry sources them from Asian manufacturers.

"I am not sure if it is a good thing if we don't know what happens in these cells," Merkel said, saying she was uncertain about relying on China. "Therefore I will try to push for a European development... Germany is ready to take part,