GPs in Scotland could be barred from becoming partners unless they spend a minimum amount of time with patients each week.
The move would make it harder for private firms and even GP-led companies to expand north of the border.
The Scottish Executive is consulting on plans to disqualify all but traditional GP practices from offering primary care in Scotland. The long-anticipated move is intended primarily to bar commercial health companies.
In the foreword to the consultation, Scottish health minister Nicola Sturgeon explained that the Executive's 'vision of a mutual model means practices that are owned by people with a direct interest in the patients they treat'.
But the plan would also prevent GPs or other health professionals from holding contracts unless they spend a 'minimum amount of time ... in the clinical care management of patients and day-to-day running of the practice'. The consultation document suggests one day a week as a reasonable figure.
There are likely to be exceptions for GPs who have retired, are on maternity leave or have taken a career break.
A spokesman for the Scottish government said that successful practices could still bid to take over vacant neighbours, 'as long as the principal GPs ensure they devote enough time to dealing with all those on the enlarged patient list'.
The plan to block commercial provision, which involves amending the 1978 NHS (Scotland) Act, would also bar voluntary providers from providing NHS primary care.
A spokeswoman for BMA Scotland welcomed the moves to bar private provision. But she said a 'number of aspects of the proposal had not been discussed with GPC Scotland'.
'We need to carefully consider their implications,' she added.
Dr James Kingsland, president of the National Association of Primary Care, said that the plan could be off-putting to entrepreneurial GPs, and could make it harder to increase capacity.
'If the quality of services in Scotland is such that it does not need that capacity, then we need to know how it has done it,' he said.
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