Northern Ireland GPC chairman Dr Tom Black said the service needed a minimum £33m recurrent funding boost to bring it up to the UK average after real-terms cuts.
The money should fund more GPs and staff and improve premises, he warned - pointing to a 63% increase in consultations since 2004.
The warning comes in a report by GPC Northern Ireland calling for change in the way primary care services are run.
The report sets out the GPC’s plans for the development of non-profit federations of practices, which will grow into provider and training organisations, partnered with specialists and offering step-up and step-down services in the community.
Federations - the establishment of which the GPC has led - will comprise around 20 practices, serving 100,000 patients.
The report said federations would provide the opportunity to lead the way in healthcare system change, ‘creating greater efficiency and effectiveness, which will result in better services for patients’.
Dr Black said: ‘We believe that federations of practices have the potential to support primary care to work at a scale needed to take on the area of integrated care required for "shift left" as envisaged in [the health department and NHS board’s policy] Transforming Your Care.
‘It is our vision that family doctors will carry on providing essential services and chronic disease management, working alongside our specialist secondary care colleagues,' said Dr Black.
‘But given that GPs are dealing with a rising workload with a diminishing workforce, the health service in Northern Ireland needs to pivot back towards a primary care-led service.
‘This will require a shift of emphasis, resource and workforce into community services. Radical change with federations of practices taking on integrated care delivery will result in the change necessary to improve patient services.’