Doctors' leaders have declared all-out opposition to the Government's NHS shake-up amid claims they will give too much influence to the private sector.

The British Medical Association (BMA) Council passed a motion expressing its "opposition to the whole Health and Social Care Bill" and calling for a public campaign of opposition.

Labour hailed the move as evidence of the Government's failure to secure the support of health professionals for the sweeping shake-up of health service commissioning.

The BMA signalled the intensification of its battle with ministers over the controversial legislation after being alarmed by recently issued draft guidance about commissioning. It said it contained "commercially-focused criteria" that would make it "almost impossible" for groups of doctors to avoid bringing in outside firms.

Urgent talks are being sought with Health Secretary Andrew Lansley over the shake-up. The BMA has previously said it would consider supporting the legislation with major revisions.

Dr Hamish Meldrum, chairman of the BMA Council, said: "A key plank of the Government's NHS reforms was to entrust GPs and other healthcare professionals to lead on the commissioning of services for patients to ensure local health needs were met.

"These latest proposals from the Government have the potential to seriously undermine this role, restricting the freedom and independence that clinically-led commissioning groups need to make locally sensitive, locally accountable, patient-focused decisions.

"Doctors tell us about the chaos they are already seeing on the ground as more and more change is implemented. The Government should be focusing on ensuring the skills and experience of staff in current PCT clusters are retained."

After debating the draft advice, the council passed the motion declaring its determination to see the legislation scrapped and calling for "rapid organisation of a public campaign of opposition". The BMA would now be "considering its next steps", it said.

A Department of Health spokeswoman said: "The BMA has misunderstood our plans for commissioning support. All commissioning decisions, including on the back-office functions of commissioning support, will be made by Clinical Commissioning Groups themselves and cannot be delegated to other organisations. So it will actually be BMA members, rather the Government, that determine what form commissioning support takes in future."