Outside eating areas are covered by the smoke free legislation - that is the belief of Barnsley council.
But MA legal guru Peter Coulson said the council is simply wrong in its assertion.
In a consultation document, entitled "Guidelines for street cafes", the council said it was considering banning smoking in outside licensed areas from 1 April.
If customers are caught smoking outside three times, the premises could lose its licence.
"One thing we wanted to achieve is the continental cafes and so we brought out the street cafe licence where people could apply for a street extension into the footpath for tables for food and for drinks to be served on a nice sunny afternoon in Barnsley," councillor Roy Miller told BBC Radio Sheffield.
"The problem we have at the moment is that some of these areas are turning into smoking areas.
"Now, when they apply for a licence for these areas serving food and alcohol the legislation is quite clear on the street cafe scene that it is seen as an extension of the existing eating facilities and as such the law regarding smoking applies to these areas."
He added: "If someone is sitting down eating some food and another person lights up at the side of them, the smoke will be blowing across at them all the time."
The councillor from Barnsley is wrongPeter CoulsonMA legal editor
MA legal editor Peter Coulson said the Health Act only banned smoking in enclosed or substantially enclosed public spaces.
"The Department of Health can designate certain other areas to be smoke free but I've been told it has no plans to do so at the moment," he said.
"The councillor from Barnsley is wrong."
Disastrous
Also appearing on BBC Radio Sheffield, MA deputy news editor John Harrington blasted the proposals as an "terrible idea" that would be a "disaster" for the pub trade.
"The trade has invested millions, absolutely millions, in gearing up outdoor areas for smokers and to be told that money has been wasted would be awful."
He added: "Licensees are acutely aware of the impact the ban is having on their business and any extension of that would be disastrous for a lot of pubs.
"Let's hope this doesn't get adopted."
Pubwatch chairman Paul McNicholas, free-of-tie lessee at Durty O'Dwyers, added: "It would be difficult to police. I hope common sense prevails."