Under the rules, if a female GP dies before her husband, he would receive a pension based only on contributions made after 1988 - any payments made before then would be worthless.
But if a male GP leaves a widow, her pension would be calculated on all contributions.
BMA pensions committee chairman Dr Andrew Dearden told the ARM that a case was being readied.
'I am happy to report that we have taken the first step towards a legal challenge to this inequitable problem,' he said.
Speaking after the event, he said: 'For the past 19 years we have been looking at a legal challenge, and two cases have now set a legal precedent so that we can do it.'
The BMA is understood to have identified potential test cases, but would not give details.
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