[MovedGoalPosts]

Well I don't know how wide the scope of your essay's coverage, but you have a wealth of subject matter even dealing with both elections where not a great deal had necessarily moved on in terms of voter choice. The Labour party were still making promises of action, whilst attempting to discredit the Tories, yet the Tories wernt really in the fight of suitable answers or credibility. The Liberal Democrats and others were just trying to throw spanners in the works. You may find your self better off limiting your subject to just one election, and even then you'll have a wealth of research to do to proove your argument accurately.

I suspect a lot of voter behaviour is about their perceptions and thus the aim of the brand is to create the perception that the choice of one party will be better, or do you less harm, than choosing another.

How you relate such behaviour / perceptions and influence of branding to the traditional consumer "purchasing decision" could well be the interesting bit.