Under existing rules, a locum who dies on a day when they are not contracted to work may not be eligible for the lump sum that would be paid out for an employed colleague or partner - despite having paid contributions in full to the NHS pension scheme.
The rules have led to a number of high-profile cases in which the families of locums who have died have been denied full benefits.
The legal challenge over death in service rights is the second legal challenge launched this year over pensions by the BMA - with the association also announcing last month it would sue the government for age discrimination over 2015 NHS pension changes.
BMA sessional GPs sub-committee deputy chair Dr Krishan Aggarwal, said: ‘Having pursued a claim for death in service benefits through the NHS pensions internal disputes procedure and onto the pensions ombudsman, the BMA continues to challenge the application of rules on behalf of a widower of a former BMA member.
‘Contracted GPs receive a full death in service benefit but if a locum GP was to work on Mondays, Wednesdays and Fridays but died on a Tuesday, NHS pensions state they were not in pensionable service at that time and therefore are not eligible to receive the full benefit. The GP in this case died on a day she was not due to work and therefore did not receive the full death in service benefit that her employed colleagues can expect.’
The BMA has not named the locum involved, but the case appears similar to one in which a 40-year-old GP died on a day off in 2015. Supporters raised thousands of pounds in support of the family of Dr Helen Sanderson after they were denied death in service benefits.
The BMA said it hoped the High Court would 'overturn the decision made by the pensions ombudsman' and rule that the GP is entitled to death in service benefits.
The association has applied for permission to appeal the ruling and is awaiting a decision from the High Court.