Essex LMCs chairman Dr Brian Balmer predicted a 'bulge' in retirement as reforms in the White Paper Liberating the NHS take effect.
'We have a lot of workaholic GPs who have kept the service running for a long time,' Dr Balmer said.
'But there will be a significant number of GPs who say this is not the kind of general practice they want to do and maybe think now is the right time to go.'
Brian Keeling, chairman of Lincolnshire Local Involvement Network, which represents patient and community groups, said the number of GPs close to retirement was 'really worrying' for quiet areas like Lincolnshire.
'We have a high number of GPs close to retirement and reforms giving a lot of extra responsibilities to them. It does not take a genius to see that people will see it as a good time to move on,' he said.
Responses to a recent survey by GP also indicate the White Paper has prompted many to consider retirement.
One GP said he had led his practice through fundholding and been active on both the LMC and PCT but had now 'had enough'.
'There is complete apathy towards this commissioning. Colleagues are looking to me and others who have previously embraced and done everything,' he wrote.
'I have now had enough and think it is time for the younger generation to move on with it.'
Another respondent said of the White Paper: '(It will) make me more likely to retire as soon as I can possibly afford to.'
Accountants also predict a number of GPs will retire early ahead of the government's review of public sector pensions.
Laurence Slavin, of specialist medical accountants Ramsay Brown and Partners, said more GPs were taking 24-hour retirement to beat any prospective changes to their pension.
'The White Paper outlined that there will be a review of pensions to ensure they are affordable and sustainable. GPs are anxious and a significant number of GPs are taking their pensions early to make sure they get them,' he said.