The Government's Health Bill will make family doctors' work "infinitely harder" and threatens to damage their relationships with patients, a GPs' leader has warned.
In a letter to all GPs in England, the chairman of the British Medical Association's (BMA) general practitioners committee Laurence Buckman called on the Government to scrap the Bill.
At a meeting this week, the committee agreed that the legislation - currently going through the House of Lords - was "complex, incoherent and not fit for purpose" and would be "irreversibly damaging to the NHS".
Downing Street said it is "confident" that the Bill will become law in England by the time of the Queen's Speech on May 9. But Liberal Democrat activists are hoping to derail the legislation by tabling a motion at their party's spring conference next week calling for it to be ditched.
The BMA has already come out in opposition to the Bill and called on GPs to write to their MPs outlining their concerns before it returns to the House of Commons later this month.
Dr Buckman said that GPs initially welcomed the plans for clinically-led commissioning, and many have already set up clinical commissioning groups (CCGs) to give their patients more choice over their treatments. But he warned: "Over time, it has become clear that this is the most top-down reorganisation the NHS has seen since its inception."
The legislation will create a "new network of bureaucracy" and "the ability for ordinary GPs to change things will diminish", he said. CCGs' budgets will be too small for them to function unless they unite into "large and remote units".
Unless GPs take an active stand, commissioning powers and the day-to-day running of CCGs are likely to be outsourced to private organisations known as CSSs which provide commissioning support services, said Dr Buckman. "We believe this will lead to the privatisation of commissioning, destroy the public health dimension to commissioning, with a loss of local accountability to local populations, and is likely to exacerbate health inequalities," he wrote.
Responding to Dr Buckman's letter, health minister Lord Howe said: "The BMA's GPs committee seems to ignore the fact that thousands of GPs, covering 95% of the country, are already getting on commissioning and improving care for their patients. Patients are being treated in more convenient places, pressure on hospitals is reducing and we are safeguarding the NHS for future generations.
"Without the Bill, we couldn't remove layers of bureaucracy and reinvest £4.5 billion into frontline patient care. And the independent NHS Future Forum found broad support for the principles of handing power to doctors and putting patients at the heart of the health system."