Consortia are likely to face legal challenges over the distribution of 'quality premiums' they will receive for good performance, according to Andrew Lockhart-Mirams, senior partner at Lockharts solicitors.
Mr Lockhart-Mirams added that a complex legal framework would be required to define practices' relationship with consortia. He pointed out that consortia may wish to eject persistent poor performers.
Ejected practices would need rights of appeal, particularly given that GPs are required to be consortium members to hold a GP contract, he said.
The White Paper Liberating the NHS expects all practices to join a consortium by 2011. Consortia will take control of commissioning by 2013.
'My first thought is that what is proposed (in the White Paper) is going to cause a lot of anxiety and friction between GPs,' said Mr Lockhart-Mirams.
'There are big issues about how quality premiums are distributed. Whether it is given out evenly to member practices, per patient, per weighted patient, per partner, or whether those performing poorly are told: "Why should you get anything at all?"
'There will be all sorts of different arrangements around the country,' he said.
Mr Lockhart-Mirams said it was naive to assume consortia will operate like existing practice-based commissioning (PBC) groups.
'By and large PBC groups have formed themselves from like-minded practices of the same standard, without inviting those who are known to be poor performers.
'It will cause a lot of difficulty to the extent that some practices may be wound up against their will because they can't manage,' he added.
Lockharts has worked with more than 2,000 GP practices and is now working on contracts for consortia forming in London and other areas.
'There needs to be a set of rules that includes both the aspirations of the best practices but also protects those that are struggling,' said Mr Lockhart-Mirams.
GPC negotiator Dr Chaand Nagpaul said that working in consortia would be a 'huge challenge' requiring practices to 'develop a more corporate mindset'. 'It will no longer be possible to think of yourself as a stand-alone practice,' he added.
NHS Alliance chairman Dr Michael Dixon said keeping consortia small would help the relationship between practices.
'We don't want lots being spent on legal fees in the system,' he said.
'The DoH has realised peer pressure is a powerful thing in general practice that has not been used much. If we define the ground rules between practices and there is good leadership, it has to be better than getting managers to beat us around the head,' he said.
There would only be problems where practices 'refuse to play ball' and are forced to work in consortia against their will, said Dr Dixon.
'The "lone rebel" who only cares for his patients is a common characteristic among GPs,' he said. 'But I think there are many that can be persuaded that this will work.'