Half a million Britons will be asked to give researchers access to their private medical records as part of a new research project.

Scientists hope the Biobank database, to be launched within weeks, will aid research into common illnesses such as heart disease, diabetes and cancer.

It will be the world's biggest resource for medical researchers, with detailed information about participants' medical histories and lifestyles.

The project will include GPs' records as well as detailed recordings of subjects' body fat levels, blood pressure and weight, New Scientist magazine reported.

Those who agree to take part will be asked to supply blood and urine samples and to fill in questionnaires about their lifestyles.

A similar project in the US, announced in 2004 by the National Human Genome Research Institute, in Maryland, also aims to store the medical histories of 500,000 people.

The organisers of the American database are considering giving participants microchip-based devices such as rings and bracelets to keep a continuous check on their heart rates and blood oxygen levels.

New Scientist reported: "Both of the projects aim to revolutionise medical research by gathering information that will allow scientists to study in unprecedented depth how our genes and environment interact over the years to cause disease."

Biobank is funded by the British Medical Research Council, the Wellcome Trust, the Department of Health and the Scottish Executive.