The survey, which received responses from 720 UK GPs, reveals most practices will cut pay per partner after this year's 0.8 per cent GMS pay award.
Some practices fear they will be forced to cut staff hours, cut services or lay off staff.
The Doctors' and Dentists' Review Body (DDRB) recommended a 1.34 per cent rise to maintain practices' income in 2010/11.
But ministers overruled the advice for the first time, awarding 0.8 per cent and calling on GPs to cut their costs by 1 per cent.
One respondent to the GP survey said there was 'no area to reduce costs without reducing services', another added 'we are already working flat out'.
Six per cent of GPs think their practice will have to make redundancies. One GP partner in the West Midlands explained: 'Apart from laying off staff, we have no efficiencies to make. Eighty per cent of our expenses are staff salaries.'
Some GPs believe savings can be made, however. One respondent said he could cut costs by 'purchasing in bulk as a consortium, and by efficient use of energy and staff hours'.
As the GPC said when the pay award was announced, it is effectively a cut for most practices. Seventy-five per cent of respondents expect profits to fall in 2010/11. 'It will fall to the partners to reduce our own pay yet again,' said one GP.
As profits fall, most practices are unsure whether they can afford to implement DDRB recommendations for staff pay.
A total of 36 per cent of GPs said their practice would not implement the suggested 1 per cent rise for salaried GPs, and 46 per cent were undecided. Just 22 per cent will raise nurse pay by the suggested 2.25 per cent.
Many respondents commented that staff morale is already low as their workload continues to rise each year.
One partner said he felt 'duty bound' to offer a small pay rise to staff and take home less himself.
GPC member Dr Helena McKeown warned that patient care could ultimately suffer as practices look to cut back non-essential activities.
'We cannot afford to do anything for charity or philanthropy any more,' she said.
Valuable activities such as medical teaching and staff training were 'soft targets' that GP practices may be forced to cut back on, she added.