Here is the Tories' latest poster, an apparent attempt to exploit Alistair Darling's "forces of hell" remark. It's true to say that voters hate divided parties, but I can't see this particular attack working.
First, while the Chancellor's frank interview with Sky News's Jeff Randall fascinated the Westminster village, it had little impact elsewhere. Most voters don't even recognise Darling.
Second, as the Guardian's Larry Elliott recently pointed out, the paradox is that the political differences between the PM and his Chancellor have actually diminished in recent weeks.
For a period, Brown was hoping to use the surplus from lower-than-expected unemployment to fund a pre-election giveaway, but he has since come over to Darling's position that any spare cash must be used to reduce the deficit.
Voters are only really troubled by personal differences between politicians when they spill over into political dispute (as in the case of Margaret Thatcher and Nigel Lawson). As No 10 and the Treasury are not, contrary to rumour, at war over next month's Budget there's no risk that policymaking will be distorted by Brown and Darling's sour relationship.
Given their position in the polls, I'd be surprised if there weren't some Tories wondering whether they would have been better off following Labour and running a largely poster-free campaign.