Insurance companies will not be able to buy patient medical records through the controversial NHS data scheme, the Health Secretary has announced.
Jeremy Hunt is to legislate on the care data programme to appease some of the concerns that have been raised about the scheme.
Mr Hunt plans to provide "rock-solid" assurance to patients that confidential information will not be sold for commercial insurance purposes, the Department of Health said.
He is to put a raft of measures in place including a statutory requirement that any patient's opt-out will be respected and legislation that will prevent the Health and Social Care Information Centre (HSCIC) - the body which will control the data - from sharing personal information where there is "not a clear health or care benefit for people".
A Department of Health spokeswoman said that this "puts beyond any doubt that the HSCIC cannot release identifiable, or potentially identifiable, patient data for commercial insurance or other purely commercial purposes."
The HSCIC will also be bound by new laws to protect patient confidentiality when anonymised data is released. And any researchers who wish to access identifiable data must demonstrate "an ethical reason to do so".
He will also give an expert body which advises on releasing identifiable patient data statutory footing.
"The principles around this programme, which will bring real benefits to patients, are fundamentally right, and we completely support them," a source close to the Health Secretary said.
"But, alongside a new campaign from NHS England to explain the programme to the public and GPs, we also need to ensure that robust legislation is in place to address their concerns."
The care.data programme was pushed back until the autumn after NHS England, the body behind the scheme, bowed to enormous pressure from patient and medical groups including the Royal College of GPs and the British Medical Association (BMA).
Patients, doctors and other professional organisations, raised concerns that they had not been given enough time to learn about the project.
NHS England has said it will work with patients and professional groups to promote awareness of the scheme.
The idea behind the programme is to link data from GP records with information from hospitals to give an idea of what happens to patients at all stages of the NHS.
The data that will be extracted from GP systems includes information on family history, vaccinations, referrals for treatment, diagnoses and information about prescriptions.
It will also include biological values such as a patient's blood pressure, body mass index and cholesterol levels. Personal confidential data will also be taken, such as date of birth, postcode, NHS number and gender. The written notes a GP makes during a consultation will not be extracted.
The data will be held by the HSCIC and anonymised by officials there. Fully anonymised data will be made available publicly to anyone outside the NHS.
Data considered to be potentially identifiable - for example where a patient in a small town has a rare disease - will only be released to approved organisations for the specific purpose of benefiting the health and social care system.
Many including a large number of medical research organisations have backed the scheme, saying it will alert the NHS when standards drop, help create a better understanding of what happens to people, especially those with long-term conditions, who are cared for away from hospital, and provide information needed to assist and support research into new medicines, prevention and treatment of disease.