The numbers of GPs will fall from 28% of the NHS doctor workforce in 2002 to just 15.5% in 2022, the RCGP said.
Chairwoman Dr Maureen Baker warned that 27m patients in England will wait a week or more for a GP appointment in 2014, because of the dramatic diversion of doctor posts from general practice to hospitals.
Between 2002-2012, the number of full-time equivalent GPs was 1.5%, while the annual uplift in hospital consultants was 4.4%.
In 2002, there were 27,200 full-time GPs, compared to 24,800 hospital consultants.
In 2012 there were 31,700 GPs compared to 38,200 hospital doctors – meaning there were 6,500 more hospital doctors than family doctors.
By 2022, the RCGP predicted that, on current trends, there would be 37,000 GPs compared to 59,000 hospital doctors – 22,000 more hospital consultants than family doctors.
Dr Baker said it was vital to ensure quick access to GPs.
‘We need to ensure that we have enough GPs to provide patients with good access to high-quality health care in local communities across the UK.
‘The dramatic diversion of doctor posts away from general practice into hospitals works against this fundamentally important principle.’
The RCGP recently revealed that spending on general practice had dropped to the lowest proportion of NHS spending ever, at 8.39%, despite accounting for 90% of NHS patient contacts.
Dr Baker said: ‘Ministers say repeatedly that we need to alleviate pressure on hospitals by delivering more care in the community, yet the numbers of posts being created for consultants and GPs is completely at odds with this.
‘If waiting times get longer, it will be more difficult for GPs to ensure that problems are caught early, and the pressure on A&E will intensify. This is bad news for patients and bad news for the whole of the NHS.’