The Centre for Workforce Intelligence, which advises the DoH on numbers of medical training posts, said GP numbers must increase if more care is to be provided in the community.
GP leaders welcomed the report, but said extra resources for practices must be provided for the goal to become a reality.
A report by the centre said the number of entry-level training posts in general practice must be increased by 450 over the next four years to reach a level of 3,250.
The centre said the increase in GP posts should be achieved by a 'significant reduction' in other areas of specialty training.
Among other cuts, 167 entry-level training posts for hospital-based specialties should be lost to make up for the rise in GP training posts, it said.
RCGP chairwoman Dr Clare Gerada said that she welcomed the report, agreeing that GP numbers must increase. She said: 'We have to respect the different demography we have, with many more people who have chronic long-term diseases, and a more elderly population.'
But GPC deputy chairman Dr Richard Vautrey warned that actually achieving an increase in GP training posts could be difficult.
'The key is how we find resources to support additional GPs when we are seeing funding cutbacks from practices,' he said.
'The message of reducing hospital-based posts to increase community posts is one that many organisations recognise. But actually achieving that is another matter.'
The BMA, meanwhile, said medical workforce planning is a 'serious issue' but said focusing on 'one or two specialties' is not the solution.
A spokesman said: 'We must look carefully at staffing levels across the NHS and adopt a coordinated workforce plan that meets the needs of the patient across a range of services.'