As Guido predicted as far back as February Labour want to define Dave as a policy chameleon.
They have even launched a site with a cute animation to go with it. Amusing, but not really devastatingly damaging. With the police raiding Downing Street, a cartoon piss-take of Dave on his bike is not going to worry him or CCHQ.

Dave wants to emphasise that the Tories have changed, Labour are pushing the message for him. As Guido said before;

Advertisers always like to keep the message simple – the New Tory message is “we have changed”. The details are irrelevant to most voters. Daz does not advertise Persil’s new formula, why is New Labour advertising New Tory policy changes?