Smokers will have to stub out in public places including clubs, pubs and restaurants when the ban comes in, and WMCs are concerned about what this could mean for their businesses.
Barry Slasberg, president of the South East Midlands branch of the Working Men's Club and Institute Union Ltd (CIU), said: "I think there might be some clubs that face closure. These are not just drinking holes, these are social centres for the community.
"Our communities have few enough places that people can go to in relative safety to socialise, and to lose a WMC is a devastating blow to any community that has one."
According to figures released yesterday, one in five working men's clubs in England and Wales fear they will be forced to close as a result of the smoking ban, while 83 per cent thought takings would fall as smokers stayed away.
Ray Eason, steward at Far Cotton WMC, said: "About 80 per cent of people using the club are smokers. It will affect our trade, there is no question about that.
"It's hard to tell by how much, but I would imagine it would be a 20 per cent reduction. I don't think we would be forced to close, because we are hoping to build an outdoor smoking area."
Michael Bott, secretary of Wootton WMC, said: "It will certainly have an affect on us. At our club there is not really anywhere we can put a shelter as we have quite a small car park.
"We will lose trade if people can't smoke, but we may get more families in with the smoke-free atmosphere."
But Barbara Chapman, committee member at Monks Park WMC in Wellingborough Road, Northampton, said her club planned to build an outdoor smoking area on the building's flat roof and was confident it would beat the ban.
She said: "I don't think people will stop coming to the club. We have a lot of people who don't smoke, and some people may bring their children. It is a family-based club. We hope that by doing the roof garden, we can accommodate everybody."