The parties seem all to have realised that using the image of their opponents is safer than using images of their own leaders, due to the inevitable spoofing that will occur, and the lack of appeal all the leaders have. Nevertheless, I reckon Labour will blow a hole in their foot with this one. I don't actually know who the fictional TV character they are using is (apparently some guy from 'Ashes to Ashes'), but they should take stock of the popularity of the show 'Life on Mars', which brought on a wave of nostalgia for the good old days, when coppers knew how to deal with wrong 'uns, and didn't give a flying fuck about political correctness.
Of course, Labour needn't concern itself with winning my vote. They've more chance of raising the Titanic with a fishing rod.