Professor Allyson Pollock, of Barts and The London School of Medicine and Dentistry, argued in the BMJ that the Bill means providers are free to charge for some elements of care that are currently NHS services.
'Providers will have extraordinary discretionary powers to define entitlement to NHS provision and charge patients,' she wrote.
'Consortia will determine which services are part of the NHS and which are chargeable, and they have been given a general power to charge.'
She also writes that the changes to the health secretary's general powers mean his 'duty to provide a comprehensive health service is abolished ... and the focus of his or her role will shift to public health functions'.
The publication of the article ends a miserable month for health secretary Andrew Lansley and his reforms.
The Liberal Democrats, and even Conservative MPs, have now joined the BMA and other medical experts calling for significant amendments to the Health Bill.