Giving evidence to the Health and Social Care Bill committee, Dr Gerada said that a combination of policies in the Health Bill would mean GPs are no longer responsible for a clear population.

'Patients will be able to register with any consortia regardless of where they live. That will bring in all sorts of issues.

‘There will be choice of consortia for patients. But there will also be consortia able to choose patients. If Mrs Jones comes to me with chronic renal failure... there may well be no one that can mandate me to take on this high-cost patient.’

She called for legislation in the Bill to be clarified to ensure these issues were resolved.

Earlier NHS chief executive Sir David Nicholson admitted that he could not guarantee consortia would not be left with PCT debts.

He said it was his ‘aspiration’ to ensure PCTs were in good financial health by the time consortia take over commissioning in 2013.

Sir David also said there would have to be 'people on the ground, locally' working for the NHS Commissioning Board for its duties as contractor of primary care and dentistry to work. 

The Health and Social Care Bill Committee is the third stage of the Bill’s passage through parliament. The cross-party committee will hear evidence calling for amendments to the Bill ahead of its third reading in the House of Commons.