On a tangent, but one that will have an impact on this debate in the future.
Advances in genetic mapping mean that inexpensive microchips will be able to test individuals for certain sequences. This will allow targeted drug treatment at the correct dosage rather than the scattergun overdosing that is the norm at the moment.It may also mean more effective preventative interventions by early diagnosis or prediction.
As someone said above, it is this low end treatment that balloons the NHS budget, rather than necessary high end treatment/operations.
It may well be that advances like these reduce the NHS budget enough to shift the terms of the debate.
Of course it could also mean that insurance companies cherry pick clients, so that some people are unable to get private healthcare, making the debate shift again. It may mean that some form of NHS or state insurance is more needed than ever.
Source for the above was a radio programme on engineers / chemists/ biologists working together and the advances they have made and were making.