What's changed over the weekend, in the light of the Lib-Dems' drubbing, is not the Coalition's willingness to re-look at the NHS reforms; it's the scale of the re-appraisal.

Having tried to do several things at once, they may now struggle to achieve just one.

Having drifted into presenting the reforms as a kind of market-led Year Zero (and allowed numerous private sector participants to hail it as such) there may now be just a series of incremental changes. But this creates its own problems.

At the heart of the NHS White Paper (July 2010) were three principles:

1) Money follows the patient, allowing GPs to choose the best care provider, cutting out the last part of the Labour-invented health bureauracy (the PCT/SHAs)

2) A focus on outcomes not inputs: so an eventual move to patient reported outcome measurements (PROMS) rather than targets for numbers of operations done

3) Clinicians rather than politicians or managers in charge of decisions on care; this meant the effective "denationalisation" of the NHS, creating an arms length body nationally and allowing failing hospitals to go bust.

The White Paper was, if nothing else, intellectually coherent. The Conservatives, in opposition, had concluded that the internal market introduced by Labour was functioning badly; failing to boost productivity; failing to bear down on costs; failing to give bang for bucks to the patient or the taxpayer.

Being Conservatives they concluded what was needed was a more perfect, less interrupted or constrained market. So they set about constructing a more pure one.

First there would be a clear "customer": the GPs, who would hold up to £80bn a year spending power on behalf of the patient.

Second there would be a clearer measure of value: PROMS - patient reported outcome measurements would replace input measurements (ie number of operations done, lengths of stay in hospital etc).

Third there would be a completely level playing field between the public and private sectors in terms of provision of the service: a free as opposed to an unfree market.

In addition the move to private and charity-sector provision would "create the largest social enterprise sector in the world" - fulfilling the touchiest, feeliest of the Big Society goals; mutually-owned clinics etc.

It's important to unpack where it's all gone wrong, and how it might be put together again, because the Bill is currently being torn apart by three sets of people: the Libdems, responding to their left-leaning voting base who want no private involvement (none at all, as Simon Hughes said yesterday); the NHS workforce and professions, who all have varying degrees of concern about the workability of the project; and Conservative health policy wonks and civil servants who fear (to their despair) that the whole thing only works if you do it all at the same time.

If you take the "pure" market as designed by Andrew Lansley, with its GP customer, its PROMS measure of value and its newly neutral stance on who can provide services, what was the ideal outcome supposed to be?

Actually it's the one numerous Labour reforms hinted at but never enacted: a publicly financed market in NHS care from which the private sector can at last make serious profits and into which, eventually, middle class customers (aka patients) can add-on services through insurance, co-payment etc.

Early on, Tory ministers and outsourcing company chiefs envisaged a mass of mutually-owned clinics (with protected pay and pension rights for the medics and nurses etc who formed them, but not for the next generation of employees); they envisaged that 30+ NHS trusts would go bust, allowing the private sector to take them over and estabilish a new footprint in the secondary healthcare sector; and that private "commissioning support" companies would swarm into the GP group practices, providing profit-generating services there.

It was supposed to be win-win. The health outcomes would get measurably better; patients would feel they had some modicum of choice; the professions, especially primary carers like GPs and practice nurses, would feel like they had a bigger stake in the NHS; the private and mutual sectors would gain access to business opportunities in the NHS.

There was only one problem. As numerous medics and health experts pointed out, there was no guarantee it would work.

The transition costs alone, in disruption, would be huge. But above that, the reason serial Labour health ministers had constrained the market, adopting state-ist rather than truly market measurements of performance, was: a pure market can go chaotically wrong, or begin to deliver benefits to the wrong participants.

So first, there's been a marked reluctance among health professionals form mutuals. As one leading consultant at a London hospital put it to me: "yes we could take over our clinic and run it ourselves; but it would pit us in competition against our neighbouring hospitals whereas our medical ethos is one of collaboration".

GPs apart, there were very few material inducements for health professionals to take part; meanwhile a few former managers were going around claiming to have enhanced their salaries by moving to the "commissioning support" sector. True or not, this has played very badly with NHS staff.

Second, there is fear among the public that the majority gets a second-class service. One health outsourcing company boss, who'd been influential with Mr Lansley at an early stage, put it to me this way: "even though there's no co-payment, what you could get are GP surgeries totally dedicated to serving professional middle aged men, specialising in prostate screening, cholesterol etc; and then next door maybe there could be a private health company offering the stuff you don't get on the NHS - prompt physio for all those squash injuries; alcohol counselling; a gym etc".

This appealed to me, put that way, as I am a professional middle aged man. But as the thought occurred to non-professional, non-sharp elbowed groups that they would be left dumped in surgeries with no middle class people at all, indeed a surfeit of the neediest and unhealthiest, the term "cherry picking" gained currency. As measures were put in place to reassure people about cherry picking, some of the advantages to the middle class (who governments are perennially worried will "desert the NHS" if they are not molycoddled) seemed to fizzle out.

Third, there is an obviously un-won argument about private provision. One boss of a private treatment centre group complained to me, during the Labour years: "The NHS is a learning organisation; we will start out beating its performance but given time it will copy us and do it cheaper; we don't need a level playing field; we need the playing field tilted in our direction." One measure he requested was to pay, like the NHS, zero VAT.

Though private provision - of core NHS services - is at the heart of the White Paper, large sections of the public remain unconvinced that this will deliver anything more than profits to the private sector at the expense of care.

One reason is that the lessons of Labour's experiment with ISTCs - factory style treatment centres staffed by indefatigable South African and Aussie eye surgeons - was not 100% successful. Outsourcing overnight GP services to private companies has, likewise, not been acclaimed as a major success.

If this argument about private provision had been aired in the general election, the government might have had less trouble winning it now; but it wasn't.

And then there are the minor, cultural niggles which turned out to be major. Many GPs don't want to be businessmen, wielding their part of the £80bn. They don't want to be part of a giant clinic but want to go on being family doctors. It took some time for this feeling to filter through to the GP organisation leaderships, but eventually it did.

Meanwhile, many patients, wondering already whether the amount of time their GP spends staring at a computer screen during consultations, were worried that the new arrangements create a conflict of interest: how does the GP take the best decision for the patient when his/her profits depend on the most efficient use of the money attached to that patient?

So, predictably once people realised what's involved, the reform has stalled. But what, logically, can be saved?

The patient-reported outcome measurement was always something that, given time, might supplant the pure measurement of inputs, if it can be proven technocratically to be better. Given time, in any kind of market - even a constrained one - a better measure of value can deliver better results.

Private involvement: well that is already looking more constrained at the level of care provision; private providers were complaining they did not have the capacity to deliver in the short term much more than 5-10% of care (Labour's ceiling on private provision, once, in the last days of Blairism before Andy Burnham took over, was 15%, if you remember). So what you could do is let the private provision angle - and the mutualism - evolve over time.

What you cannot do is compromise half-and-half on who spends the budget. Either it is the old commissioning system, half dismantled but now having to be reinstated; or a new one based on GPs. To save the latter proposal you would have to address the problem of conflict of interest, cherry picking and place a limit on the amount of a GP's budget that can be spent on "commissioning support".

The problem is, then, none of this becomes a revolution; it becomes a technocratic evolution of the old system by trial and error.

But then what you do not need is the "denationalisation" of the NHS. This has been at the heart of the White Paper, and is what many of the Royal Colleges etc are worried about; creating an arms' length service, where the NHS is not controlled by politicians; where there is no duty of the Secretary of State to provide healthcare as now; and where a hospital can - like a university - go bust, disappear, be privatised etc.

The White Paper's problem lay in trying to do many things at once: solve a productivity problem; a health outcomes problem; to create biggest mutual sector in world; to mend what they said was a malfunctioning half-market system; and to save money - all at the same time. We will never know if the system as designed would have worked, because it is already clear parts of it will not get through.

If you started with just one of the aims outlined above it would choose itself: saving money is a given; and health outcomes are the only measure the public actually cares about.

All the rest could be scrapped, or left to evolutionary non-legislative change if you wanted to. But it would not exactly be a great example in systems design, and you could not present it as Year Zero.

Finally there is a missing player in all this: Labour. Apart from campaigning to "defend frontline services" and stop an "expensive top down reorganisation" there is little sign of a comprehensive policy (it's in review of course). As 2015 gets closer, health professionals are going to want to know how much of what gets through this year Labour would unpick.

There are huge strategic problems facing healthcare in Britian: fiscal austerity, an ageing population, the patchy outcomes of the present system and the growing expectations of patients; de facto rationing; plus the timebomb of an essentially privatised adult social care system.

What they demand is a comprehensive strategy. What's probable now is that we get a less comprehensive one.