Chris Huhne's successor as Energy Secretary's described his decision to stand down from the cabinet as a sad day for Whitehall.

Ed Davey says Mr Huhne had a real vision for a green economy - but he's facing charges of perverting the course of justice over allegations his ex-wife took a speeding penalty for him.

Environmental groups say Mr Davey will have to hit the ground running - but he says he's ready.