The biggest overhaul of the NHS in its history has been labelled a huge gamble by critics, but the government says the reforms were a necessity and will save more than £5bn (€5.9bn; $7.9bn) over the next three years.

The Health and Social Care Bill went before parliament on 19 January and transforms the NHS in England. By April 2013 GP led commissioning consortiums will have control of 80% of the total health budget and be responsible for buying in patient care. They will be overseen by a new independent NHS Commissioning Board, which will be headed by David Nicholson, the current NHS chief executive.

Health secretary Andrew Lansley said: “Modernising the NHS is a necessity, not an option—in order to meet rising need in the future, we need to make changes.” He said he was shifting responsibility away from the centre and ensuring decisions and accountability moved closer to the patient.

Other measures included in the 570 page bill are:

• The NHS Commissioning Board will commission some services, such as dentistry, and will hold the consortiums to account

• Each local authority will set up a health and wellbeing board to present local views and draw up a health and wellbeing strategy for the local area

• Healthwatch England will be set up within the Care Quality Commission to help patients complain and guide them on healthcare choices

• All hospital trusts to be foundation trusts by 2014

• Cap on how much a foundation trust can earn from private patients to be abolished.

The impact assessment issued alongside the bill …