Dr Ron Singer, president of the Medical Practitioners' Union (MPU), part of giant healthcare union Unite, said GPs often found the BMA response to change too slow.
‘The wheels of the BMA often turn rather slowly,’ he said.
Dr Singer said it may now be down to rival unions, such as the MPU, to take the lead on pension protests. ‘If we give a lead often the BMA will follow,’ he added.
As many as three million public sector workers could take part in industrial action on 30 November after leading unions announced plans to ballot their members over strikes. The BMA has decided not to ballot members over taking part.
But Unite will be consulting all members including those in the MPU. Dr Singer said GP members were likely to show their support without taking part in strikes.
‘In the past members have staged some sort of action, such as leaving work at lunchtime to stage a short demonstration,’ Dr Singer said.
A BMA spokesman argued that the BMA had been active in its opposition to pension reform. ‘We've worked very hard to raise awareness of these unfair and unnecessary reforms and to publicly express doctors' opposition,’ he said.
The BMA was working closely with other unions ahead of the day of action on 30 November, he said, adding that GP membership of the BMA had grown by nearly 4% in the last year.
Meanwhile, Dr Singer said the MPU had seen a rise in locum and salaried GPs joining in the last year. ‘I would have thought around 70-100 have joined so far,’ he said.
The increase comes as the National Association of Sessional GPs (NASGP) has been actively encouraging members to join the MPU as an alternative to the BMA.
Dr Richard Fieldhouse, chairman of the NASGP said: ‘Having more than one provider is always going to be a healthy option. Of course, GPs can still be members of both.’
