Workers at the Mini factory in Cowley are to build several hundred cars without engines, transmissions or fuel tanks.

They will be shipped from Oxford to Munich, Germany, to be transformed into electric cars.

After a year of tests, Mini owner BMW will decide which technology to plump for.

Last night Mini bosses were staying tight-lipped about the ultimate destination of the cars, once testing is complete. However, motoring industry insiders suggested they would go to California, which has passed a law requiring car manufacturers to build 7,500 non-polluting cars by 2014.

The move to electric cars marks a sharp u-turn by BMW, which until recently was campaigning against tough new European emission controls.

It said the fuel of the future was hydrogen, and insisted that it was up to individual governments to create a network of hydrogen filling stations.

Since then, it has bowed to increasing pressure from environmentalists and moved to build lower emission vehicles. Its star performer is the Cowley-built diesel Mini, which has such low emissions that it is exempt from the London congestion charge.

Announcing the electric Mini tests, BMW chairman Norbert Reithofer said: "This step will allow the BMW Group to gain an initial knowledge of how mobility can be achieved efficiently using purely electrically powered vehicles.

"Our task here is to combine the ultimate driving experience with an efficient electrified drive with practically no emissions."

BMW said it would release details of the drive concept and its marketing towards the end of the year.

Oxford Mini plant spokesman Rebecca Baxter declined to comment on a report by US magazine Auto- motive News that 490 of the cars would be leased "to selected customers" and the remaining ones used as show cars.

Lightning Car Company, based in Peterborough, is to launch Europe's first electric sports car at the Motor Show in London later this month.

For boy racers embarrassed at driving something that sounds like a milk float, it will supply special "revving" sound effects.