A court action could block the controversial transfer of data from practices to NHS Digital, campaigners announced last night.

The Doctors’ Association UK has joined other campaign groups, including the National Pensioners Convention, in threatening a legal action, alleging there is inadequate patient consent for the transfer. Other campaigners include openDemocracy and Conservative MP David Davis.

Other medical organisations have called on NHS Digital to delay the transfer due on 1 July. Patients have been given until 23 June to opt out. The project was announced on 12 May.

GP Dr Rosie Shire, from the Doctors’ Association UK, said: “GPs were barely informed of this major change – how are patients expected to know about it? DAUK supports safe, consensual uses of patient data, including for health research. But we want to see it done in a way that keeps faith with patient trust and won’t erode the relationship between clinician and doctor. Patients need to give informed consent to their data being used. We can’t see why the government won’t do this in a less rushed and more transparent way.”

Diarmaid McDonald, from campaign group Just Treatment, said: “Every single NHS patient we work with was completely shocked to hear this was happening – and very angry. Nearly all of us have sat down with our GP and had deeply personal conversations about life changing health issues. For the government to seize our GP records in this way, allowing unknown companies to commercialise that data, with no consultation is insulting and puts trust in GPs at real risk. But for many patients this is not just about their data – it’s about the future of the NHS. We’re sleepwalking into a health system where profits are prioritised over patients, with big tech and pharma corporations at the helm, shaping every decision about the care NHS patients receive.”