The college has calculated that overall GP funding will see nine-figure losses at a time of increasing demands on the profession.
RCGP chairwoman Dr Clare Gerada called on the government to invest in general practice 'to guarantee safe and effective care for our patients today and in the future'.
The GPC warned last month that GPs could see a further £200m stripped from general practice next year over plans to equalise funding across GMS and PMS contracts.
Figures from the NHS Information Centre show total investment in general practice in England was £8.4bn in 2011/12, a 1.2% fall on the previous year.
The RCGP estimates that if this trend continues, £196m will be lost from GP service funding by 2015/16.
Dr Gerada said general practice was 'the most effective and cost-effective way of providing patient care', with a whole day's care costing one tenth of a day in hospital.
'But funding and resources for our services is being stretched to the limits, with family doctors facing ballooning workloads, record hours being worked in surgery and real consequences for patient care,' she said.
She said funding must reflect the increasingly challengign and complex work undertaken in primary care as the population ages and patients present with multiple conditions.
Source: NHS Information Centre, RCGP calculations