Northern Ireland GPC chairman Dr Brian Dunn said that local GPs were 'dismayed' by the income reduction, outlined by assembly government health minister Michael McGimpsey and due to come in with immediate effect.
Dr Dunn estimates the average practice will lose up to £10,000 from cuts to enhanced services and locum costs.
'This is coming four months into the financial year,' he said. 'GP practices have made plans accordingly, expecting this income for the rest of the year,' he said.
The cuts will lead to reduced services in general practice and ultimately cost the health service money in the long term, he added.
'Minister McGimpsey has repeatedly promised to protect front-line health services. If general practice and the services it provides is not a front-line service then I do not know what is. Patients are going to suffer,' said Dr Dunn.
'GPs want to provide as much treatment as possible to people in the community, but this cut may well result in an increase in hospital admissions and a decreased ability of practices to co-operate with schemes that allow shorter hospital stays, leading to increased costs to the health service,' he said.