Tacked on at the end of the Health and Social Care Bill, now going through Parliament, is a clause which gives the health secretary far-reaching powers to make regulations controlling and prescribing who should be given access to patient information.
Clause 59 would also allow the health secretary to make regulations overriding the duty of confidentiality to patients, which now exists under common law, and to pass on identifiable patient information without the patient's consent if he deems this to be for the general good.
Data used in line with the regulations would be deemed to be used lawfully, despite common law duties which require doctors and health service workers to respect patients' confidentiality.
The Department of Health wants to be able to pass on identifiable patient information to cancer registries and other disease registries without having to ask for the patient's consent. It also wants to stop data being used for purposes it deems detrimental to the NHS.
The clause is aimed at plugging what the DoH regards as a loophole which emerged from the Source Informatics case, in which a data company paid pharmacists to provide information on GPs' prescribing practices for sale to pharmaceutical companies. The Court of Appeal held that there was no breach of confidentiality because the information was anonymised.
But the clause is proving highly controversial. Among its opponents are the Association of Community Health Councils for England and Wales, which is against any move allowing patients' information to be released without consent.
Liberal Democrat health spokesman Paul Burstow is calling for the clause to be scrapped.
And data company IMS Health, which specialises in collecting and disseminating anonymised data, says the clause threatens the ability of patient organisations, academics and the pharmaceutical industry to carry out anonymous research, and could encourage ministers to suppress inconvenient information.
There has been no consultation in advance on the clause, though the government is promising to consult on any regulations it proposes to make under the powers.
This ministerial power grab warrants a close watch.