Cameron needs to be the reasonable statesman on tonight’s debate

Which David Cameron will take the stage for tonight’s seven-way showdown? Will it be the competent, likeable and reasonable statesman who has steered the economy onto safer ground? Or the tetchy one who calls Ed Miliband a ‘waste of space’ at Prime Minister’s Questions?

On Monday, speaking at a lectern outside the door of Number 10, the Prime Minister decided to launch a personal attack on his opposite number rather than make a statesman-like pitch to the electorate. To have mentioned Ed Miliband by name once would have been historic – doing so three times smacked of desperation.

Criticising opponents is entirely legitimate, but the hostility of these attacks raises the question of whether David Cameron is - to use his own word - so ‘reasonable’ after all? Certainly the Tory description of a Labour future has become increasingly farfetched.