Dr David Jenner, PBC lead for the organisation, believes the Framework for External Support for Commissioners is the government's 'plan B' if PBC does not gain support after the Darzi review.
The framework allows PCTs to choose from 14 approved private companies to support commissioning.
Last week, Northamptonshire PCT announced that it has employed UnitedHealth to commission health services for its local population.
'PBC has one more chance before commissioning is handed to multinational companies,' Dr Jenner told delegates in London at the launch of the NHS Alliance's 'A Vision for Practice Based Commissioning' document last week.
'It is a useful reminder for those who don't get involved. Disinterested and doubting GPs could kill PBC.'
Private companies working as commissioners could succeed as long as there is not a 'master and slave' relationship between the company and local GPs, he added.
The NHS Alliance report also proposes more accessible innovation funds and improved freedom for mature PBC clusters.
Speaking at the conference, health minister Ben Bradshaw said the DoH agreed with 98 per cent of what the NHS Alliance proposed.
But Dr Jenner raised concerns about how practices would co-operate in PBC clusters when the government wants them to compete.
He also warned of Conservative plans to make PBC budgets compulsory if they come to power in the next election.
'The Tories would make managing PBC budgets compulsory, with full accountability,' he said.
'You would be performance managed on your ability to manage that budget efficiently, possibly resulting in the loss of your core contract.'
To complete a gloomy outlook on the future of PBC, Dr Jenner added that the war between the BMA and the DoH was hindering its progress and needed to be resolved quickly.
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