What are they like inside?

The Volt’s dashboard looks suitably space-age. The gleaming white centre console is covered with touch-sensitive pads, which control everything from the stereo to the climate control system.

Trouble is, the fancy design isn’t very user-friendly, because all the buttons look identical and aren’t easy to hit at a glance. Worse still, the thick and steeply-angled windscreen pillars compromise your view out.

By comparison, the Prius’s interior looks dreary; there are too many grey, cheap-feeling plastics throughout. However, the digital display atop the dashboard gives you lots of information – everything from your remaining range to a graphic showing how the drivetrain is working. The centre console is much easier to fathom than the Volt’s, too.

The Prius is the more practical car. It can seat five (one more than the Volt) and rear passengers have loads more room. The Toyota also has the larger and more useable boot; there’s more outright space, and there isn’t a big step down on to the boot floor like there is in the Volt.