Controversial plans to share medical records will be delayed until later this year “to allow more time to build understanding of the benefits of using the information”, health officials have said.

Pressure has been mounting on NHS England, the body behind the scheme, after doctors leaders said patients need to know how their data will be used outside the NHS.

Both the British Medical Association and the Royal College of GPs have warned patients are being kept in the dark about the plans.

Concerns about the data pool mirror privacy worries first expressed in Wirral six years ago.

Back in the summer of 2008, Wirral’s Primary Care Trust was deluged with complaints about its “Wirral Keep Well” scheme – which turned out to be a privately-run telephone health advice line owned by a company based in Boston, Massachusetts.

Every household in the borough was sent a postcard by the PCT informing them of the project.

But unless people wrote to their doctor saying they wanted to “opt-out,” their confidential health information would have been sent to a private call centre run by the American firm in Cambridge.

NHS England said that national roll out of the scheme, that was due to take place in April, will now happen later this year.

A spokesman said: “To ensure concerns [of various groups]are met, NHS England will begin collecting data from GP surgeries in the Autumn, instead of April, to allow more time to build understanding of the benefits of using the information, what safeguards are in place, and how people can opt out if they choose to.”

Patients, doctors and other professional organisations, have raised concerns that they have 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.

"We have been told very clearly that patients need more time to learn about the benefits of sharing information and their right to object to their information being shared," said Tim Kelsey, national director for patients and information at NHS England.

"That is why we are extending the public awareness campaign by an extra six months."

Chaand Nagpaul, chairman of the British Medical Association's general practitioners committee, said: "With just weeks to go until the uploading of patient data was scheduled to begin, it was clear from GPs on the ground that patients remain inadequately informed about the implications of care.data.

“While the BMA is supportive of using anonymised data to plan and improve the quality of NHS care for patients, this must only be done with the support and consent of the public, and it is only right that they fully understand what the proposals mean to them and what their rights are if they do not wish their data to be extracted.”

Nick Pickles, director of Big Brother Watch, said: “NHS England has failed to properly communicate to patients or GPs what this new database involves, how it affects our medical records and what the risks are.

“The scheme’s benefits are no justification for not properly informing people what will happen and a delay is the right thing to do to maintain public confidence and ensure people have an opportunity to opt-out.

“Our medical records contain some of our most private information and any changes to how they are used should not be rushed into.

“NHS England should now write to patients individually, including an opt-out form, explaining the scheme and allowing people to make an informed choice about what happens to their medical records.”