The Home Office has obtained the personal data of thousands of NHS patients as part of a Government crackdown on illegal immigration.

Details of an agreement between the health service and the Home Office allowing requests for information on suspected immigration offenders has been made public for the first time.

Non-clinical details that can be sought from NHS Digital include names, dates of birth and the individual's last known address.

Between September and November, the Home Office made 2,224 requests. In 1,659 instances details were traced, in 516 there was no trace, while 69 requests were turned down.

This represents a threefold rise in requests since 2014 amid Government attempts led by Theresa May to toughen immigration policy, reported The Guardian.

The practice has been called “unacceptable” by Shadow Home Secretary Diane Abbott.

“We have already seen this Government using schools to gather immigration data on children. Now we find they are using the NHS in the same way,” she said.

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“Other public services should not be expected to cover for this Tory Government's cuts to the border agency.”

Information may be requested in relation to those who have failed to comply with reporting restrictions, absconded from immigration control, escaped from detention, exceeded their time limit to stay in the UK or sought to obtain leave to remain by deception.

The memo states that the Home Office can only request information in cases where the person in question is not in contact with authorities and “other reasonable and appropriate efforts to locate them have failed”.

It says NHS Digital retains the right to seek more information if necessary, adding: “Without limitation, NHS Digital may refuse a request for information from the Home Office if it is not satisfied that the request is in the public interest.”

A Government spokesman said: “We share limited information between health agencies and the Home Office to trace immigration offenders and vulnerable people, and prevent those without the right to access benefits and services doing so at the expense of the UK taxpayer.

“Access to this information is strictly controlled, with strong legal safeguards.

“No clinical information is shared, and before anything at all is shared, there has to be a legal basis to do so.”