Jackie Ashley in the Guardian today has a post about how Cameron has manoeuvred into a strong position in the past year, which I think is true. I said way back that this is what he specialises in - not the skills of Government but the skills of manipulating electoral politics.
However, this is my image to conceptualise where he is. Remember in the film Aliens when they set up robotic machine-guns to shoot down any alien which attacks down the main corridor. The guns fire over and over again - but the aliens keep coming, over the bodies of their fallen comrades. The guns rattle through all the ammunition rounds and are about to run out completely, when the aliens give up, and withdraw. It's one bit of good luck the marines get in the whole film. The aliens are clever, but they didn't realise how close they got to a break-through.
Well I would put Cameron's Government in the position of the marines (which makes me an alien, but I'll go with that image). Or to continue the previous analogy, they are a space-pod without a heat shield. They have had to use up all their resources to get to this stage. But now the economic disaster they have created is about to manifest, and they have nothing left to burn.
Well, one or two things. They will burn up Lansley over the NHS, and there will be a little trail of symbolic human sacrifices from the Cabinet, as there was under Thatcher. They may jettison Scotland from the Union to save themselves, which is pretty desperate and destructive IMHO. Their main strategy of course is to save up a little pot of money, and then flood it back into the economy in about three years to produce an illusory bubble of growth (like taking blood from a victim, and then right at the end, transfusing some of it back in). There's the redrawing of boundaries.
So, they are not out of desperate strategies yet: the guns have one or two rounds. However, when someone is resorting to a series of strategic sacrifices just to stand still, they are in more trouble than it appears. We are like the aliens in the corridor, and if we can break through, it's marine-munching time.