I suppose its possible, but i can't see too many switching to the opposite team.
and purely because the lib dems have sided with the conservatives, SOME lib dems will dislike that a lot, and vote elsewhere.
personally i'm not as bitter as that, and if it works well, and i agree with the things done in this coalition, I would even consider voting for a libcon government next time around (if it were an option, and if they do a good job remains to be seen) for me, it's more about what is best for the country, and issues which directly influence my life. things done to high earners won't impact on my life too much, but tax for the lower paid jobs does. maybe in 10 years time that will change, but at the moment, thats how it stands. I do believe however, that if you could have a different tax level for people who are secure, that might work, e.g. if someone owns their own home, has completely paid the mortgage, and has no other debt, they could potentially be taxed more than someone with 15 years left on their mortgage and £25k of debt, obviously it would have to be minimal, otherise people wouldn't bother getting themselves financially sound, and in practice it probably wouldn't work (and voters wouldn't like it either). my point is, in my current situation, where we can't afford to rent, let alone buy, have porr credit rating, etc, a small tax break would allow us to sort things out quicker and easier. whereas someone in my stepdads situation, where he owns a £1m house on a few acres, no mortgage to pay, no phone bill to pay since he gets it free, no mobile phone bill (free) a company car, and earning around £200k a year, could afford to give up some of the money for the good of the country, with out too much impact on lifestyle.
I realise that if was earning that much, I would probably argue against myself there, saying that I work hard for every penny, why should the government take more from me when I obviously work much harder for it... but the point still remains valid, even if it would be unpopular.