Hippocrates's injunction to "first, do no harm" applies as much to governments as it does to physicians but it has been conspicuously ignored by Andrew Lansley. The Health Secretary's chaotic reforms, for which, it bears repeating, the coalition has no mandate, threaten to result in the biggest crisis in the NHS since the service was founded. For this reason, more than 12 months after it was introduced in the House of Commons, the Health and Social Care Bill continues to lack the support of either the medical profession or the public. In the past month, the Royal College of Nursing, the Royal College of Midwives and the Chartered Society of Physiotherapy have joined the British Medical Association (BMA) and the Royal College of GPs in calling for the legislation to be scrapped.

David Cameron dismisses such groups as mere "producer interests". The medical profession has indeed often been resistant to change. It was only after Aneurin Bevan, in his own words, "stuffed their mouths with gold" that BMA members dropped their objections to the creation of the NHS. But it is the range and persistence of the opposition to the reforms that distinguishes it from the usual public-sector obstructionism.

The government's decision to carry out the biggest top-down reorganisation in the service's history would have been questionable in times of plenty but it is absurd in times of famine. The NHS is simultaneously required to make record efficiency savings of £20bn and to implement thegovernment's costly and bureaucratic reforms. In its excoriating report on the changes, the health select committee, chaired by the respected Conservative former health secretary Stephen Dorrell, warned that the reforms were acting as "a disruption and distraction" and impairing the NHS's ability to make savings. The cost of Mr Lansley's plan is now estimated at £3.4bn, £2bn more than initially stated.

Concurrently, waiting times have already risen after the coalition relaxed Labour's much-derided but effective central targets. The number of patients not being treated within 18 weeks, a right enshrined in the NHS constitution, has increased by 43 per cent since May 2010 to 29,508. The "perfect storm" envisaged by Hamish Meldrum, head of the BMA, in his interview with the New Statesman last week is coming into view. He warned that the strain on the service will lead to more disasters such as the one at Mid Staffordshire NHS Trust, where patients, in the words of an independent inquiry, were left "sobbing and humiliated".

Despite an elaborate "pause" last summer, the bill's "fundamental principles" remain in place. The requirement for the new GP consortiums to commission services from "any qualified provider" opens the way for full-scale privatisation. The principles of universality and comprehensiveness on which the NHS was founded will be discarded as the service is transformed into a market free-for-all. Little wonder that Kingsley Manning of the health firm Tribal has welcomed the reforms as the "denationalisation" of the NHS.

Mr Cameron worked hard in opposition to convince the public that the Tories could be trusted with the health service. Yet the zeal with which his government has pursued these reforms has undermined his earlier reassurances. Mr Lansley's supporters, determined not to lose face, insist that it is "too late" to abandon the bill but that is precisely what the government should do. No reasonable person believes that the NHS, subject to enormous demographic pressures, can be preserved in aspic, but these reforms will exacerbate, rather than diminish, its challenges. Mr Cameron once spoke of his desire to put an end to "pointless reorganisations" of the health service. He will not get a better chance than this.