DENVER -- Customers may be allowed to smoke cigarettes inside after some bars and taverns may have found a loophole in Colorado's smoking ban.

A judge recently ruled in favor of a Durango bar, giving owners the right to allow smoking inside under the cigar bar exemption.

Dozens of other businesses are seeking a similar exemption.

The owners of Rodney's in Cherry Creek North said they have experienced a 22 percent increase in both of its locations since the smoking ban passed in July.

However, business is far from booming at Nob Hill Tavern in Denver.

"We've never had a down year here and I've owned it for 37 years," said John Plessinger, owner of Nob Hill Tavern. "But ever since July 1 when it when in went in effect, business dropped immediately 30 percent."

Plessinger said he agrees with the judge in Durango who ruled that a local bar could continue to allow smoking under the assertion that five percent of its sales come from cigarettes. The judge said the five percent cigar exemption is ambiguous when referring to tobacco.

"(The exemption) is specific to cigar tobacco and cigarettes were not intended to be included in that portion of the definition and that is what my bill addresses," said state Rep. Ellen Roberts.

A bill on the opposite side would allow smoking in small mom and pop taverns like Nob Hill Tavern; establishments that don't have grills and don't allow minors. Its sponsor believes the current cigar bar exemption caters to upscale venues that most Coloradans don't frequent.

"Many of the people here in the state of Colorado like to have a beer and a cigarette. And this is a beer and cigarette bill, not a cigar and martini bill," said Sen. Lois Tochtrop.

The executive director of the Tobacco Education and Prevention Alliance said any attempt to weaken the smoking ban is concerning.

There are at least five proposed smoking ban amendments or clarifications scheduled to be heard by Colorado lawmakers in the first few weeks of February.