Under the plans, GPs could be struck off even if regulators could not prove beyond reasonable doubt that they were unfit to practise.
CMO Sir Liam Donaldson said the standard of proof for imposing disciplinary procedures should be reduced to the civil standard of 'balance of probability'.
The move mirrors recommendations by Dame Janet Smith in the fifth Shipman report, and aims to end cases where doctors cause serious concern to patients or colleagues, but cannot be struck off because a case cannot definitively be proved against them.
BMA chairman Mr James Johnson said the move 'opens the door to miscarriages of justice'.
The proposals also include a stricter regime of testing, which could see GPs undergo knowledge tests devised by the RCGP every five years, and tougher appraisals including explicit judgments about appraisees' performances.
GP leaders warned that the plans create an incentive for older doctors to quit after staying on to benefit from the new GMS contract.
Earlier this year, they warned that many would go now that GMS earnings had peaked (GP, 19 May).
The potential effects are serious. More than 5 per cent of UK GPs are aged over 60, and the figure for England is 8.6 per cent. More than a third of the 31,798 GPs across the UK are over 50.
GPC member Dr Nigel Watson said: 'GPs over 50 are often not working for the money, but because they enjoy the job. If they make it easier to suspend GPs, a lot of general practice will not like that.'
He added that heavy monitoring of GPs' performances would be 'hugely expensive' and bring no guarantees of identifying truly dangerous doctors.
GPC deputy chairman Dr Laurence Buckman said that if the new system created 'more hurdles and monitoring', many GPs would be unhappy and some could quit.
Despite concerns about the revalidation mechanism, the RCGP pledged to make it 'workable and supportive'.