If, and it's quite a big if, this country ends up in so much financial pooh that the IMF steps in then the British government (of whatever colour) will have pretty much no choice but to do what it is told. If that includes reducing all public sector pay and pensions, then they will have to do so. That gentlemen is how serious it could get/is getting.
Any consequences of such actions will simply have to be bourne, even if that includes mass resignations in the whole public sector, and no doubt the British government will try to blame the IMF for forcing actions upon them, and, if it is a Tory government, the actions of previous Labour administrations for getting us to this point.
That is how badly things could end up if the politicians of all parties don't grasp the nettle of government debt reduction - and not being honest about the scale of the problem in the PBR, on the basis there is an election looming and you don't want to frighten the voters, is, in my opinion, totally dishonest, typical of NewLiabour and possibly of all politicians.
I heard somebody say something the other day that struck a chord with me. The government of the day (currently Labour) don't own the country. They merely have stewardship of it for 5 years, and all their actions and decisions should be made in the best interests of the country and all its inhabitants not their own political party and traditional voters! Sound like a good principle to me, just a pity they don't follow it!