GPonline reported earlier this year that Operose Health - a subsidiary of US healthcare giant the Centene Corporation - had expanded its portfolio of NHS GP practices to 58 through a takeover deal with major primary care provider AT Medics.
Lawyers representing a patient at one of the practices affected have submitted papers seeking a judicial review into the decision to approve the takeover - citing concerns over consultation with patients, patient data and the potential impact on services.
Anjna Khurana, the patient at Hanley Primary Care Centre in Islington who is behind the judicial review bid, said she was calling for the decision to allow the change of control of practices to be 'declared unlawful'.
The bid to secure a judicial review is focused on just eight of the practices taken over as part of the deal with AT Medics - practices in the North Central London CCG area.
A crowdfunding appeal set up by campaigners backing the legal challenge had raised more than £40,000 by midday on 25 May - just days after its launch.
The deal with AT Medics made Operose almost certainly the largest provider of NHS GP services in England - with nearly 1% of the total 6,658 practices in the country under its control, covering a total patient population in excess of 500,000.
The expansion of Centene's foothold in NHS primary care has sparked concern among GPs, with the Doctors in Unite union warning the health service was being 'parcelled up and sold off under the radar', and the Labour party calling for an end to 'stealth privatisation' of GP services.
GPs led a protest backed by MPs and campaigners earlier this year over the Operose deal with AT Medics.
Ms Khurana said: 'I am so afraid that our NHS is being dismantled bit by bit, with the private sector playing a bigger and bigger part.'
London GP Dr Louise Irvine said: 'The NHS Constitution demands transparency and people rightly expect accountability in NHS decision-making especially about such important matters as who runs our GP practices.'
Anna Dews, a solicitor at Leigh Day who is representing Ms Khurana, said: 'Our client is genuinely concerned that the decision to approve the change of control at AT Medics Limited has been conducted unlawfully.
'There has been an extremely limited opportunity for public scrutiny, despite the obvious ramifications for patients. The public have a right to be involved in decisions such as this, especially when it involves changing circumstances surrounding their highly sensitive health data.'
A spokesperson for Operose Health told GPonline earlier this year: 'AT Medics and Operose Health have formed a partnership in order to create the leading provider of NHS primary care services in the UK. The new partnership is committed to achieving high quality clinical outcomes and standards of care for our patients and communities.'
Operose Health said patients would 'continue to receive the same excellent standards of care' and that all necessary regulatory steps had been followed.
The spokesperson added: 'Day-to-day operations of our GP surgeries, the care that we deliver to our patients and the services accessed through our surgeries will not change. Patients will continue to consult with us in the same way that they do today. Our practice teams will be the same and all of the AT Medics leadership team are staying with the organisation as part of our new partnership.'