The government is expected to say that it will become mandatory to wear a face covering in shops from 24 July, with people failing to comply facing a potential £100 fine.
Face coverings have been mandatory on public transport in England since 15 June.
But polling by the BMA shows that almost nine in 10 doctors believe face coverings should be mandatory in all areas where the public cannot or will not social distance.
BMA chair Dr Chaand Nagpaul called for rules on mandatory face coverings to extend beyond shops - and warned that the 11-day delay in implementing the policy will endanger lives.
He said: 'For months doctors at the BMA have called on the government to stop equivocating and to ask people to wear face coverings over their mouths and noses in public places where they cannot safely socially distance.
'However, why is it waiting another 11 days to implement this policy, when the risk from COVID-19 remains present right now? This needs to happen immediately given that each day that goes by adds to the risk of spread and endangers lives. The BMA also believes that the wearing of face coverings should be extended to all settings where people cannot maintain physical distancing.'
Dr Nagpaul pointed to Office for National Statistics data that show around 1,700 new cases of coronavirus in England per day, and said this showed that 'a lot more needs to be done before we can say this infection is anywhere near being under long-term control'.
He added: 'Making it mandatory to wear nose and mouth coverings isn’t a fix all, but it will significantly reduce the risk of catching the virus for millions of people and will also help our economy and our health service.'
Of more than 5,000 doctors in England and Wales polled by the BMA, 86% said it should be mandatory to wear face masks in places where social distancing is not possible or where people are not willing to socially distance.
Around 120 countries are believed to have made wearing of face coverings mandatory since the COVID-19 pandemic began.