Generally speaking in British politics the governement is ousted when the public irrationally feel the need for a change, the policies.opposition are largely irrelevant, especially now. Blair and co realised that Labour needed to become the Tories in order to get elected so really you have the 2 main parties offering pretty much the same thing, occupying the middle ground. Elections are decided by Middle England, they trusted Blair in 1997, that trust I think has expired and Middle England will switch back to their traditional ground. Most voters never change their vote so it's the middle ground and marginals that decide. I don't think much of Cameron particularly but I will vote Tory because no other parties have convinced me. However my disdain for politicains is conststant across the spectrum, I think their main aim is to extract as much from the public purse as they can, everything else came second. The Tories will win because the public have decided it's their turn, don't look for any rationale!