Andrew Grice has a very interesting column in today's Independent based on a look at Labour's private polling. As always with internal polling, you can't be sure you are getting the whole story.
Grice uses the data to provide insight on the question of whether Cameron has sealed the deal or not; his conclusion is not yet. One particular line in the piece, though, jumped out at me:
This creates a dilemma for the Tories. The Tories are keen, for reasons George Osborne set out in a Times op-ed back in 2004, to keep their leader away from the most sharp edged attacks. They want to keep Cameron a little bit above the fray, to give him a statesman-like air. But if this charge--which is a potent one--doesn't come from Cameron, then people aren't taking notice of it.“
"Labour's research suggests voters are open to the Tory dividing line of "Tory honesty versus Labour dishonesty" when it is run by Mr Cameron, but not when it is drawn by the shadow Chancellor, George Osborne."
This problem is a consequence of the Tories using Cameron for every big and serious announcement. They have created a sense amongst the media and the public that if it doesn't come from Cameron, it doesn't matter.
The Tories need to address this problem before the campaign proper gets under way. Otherwise they will constantly have to decide which is more important to them: the attack or Cameron's image.