If you live very close to your place of work and will never ever ever need to travel more than a hundred miles or so, an electric city car is a good idea on a lease scheme. If you think that you might at some time like a spare vehicle to use for an emergency dash across the country, then you have to get an ICE car really.
An electric city car as a third car I would understand, but I'd never have one as a second car or if I new I'd be pushing the limits on the commute. When you can get a Smart for £99 a month and it'll be cheap as anything on fuel, I'm not sure I'd look elsewhere.