City commissioners Tuesday night moved ahead on changes to the city’s workplace smoking ban despite warnings from an attorney representing the hospitality industry that the ordinance was unconstitutional.

Dan Owen, an attorney representing the Lawrence-based Kansas Licensed Beverage Assn., said the ban has been flawed since its inception last year because it punishes bar and restaurant owners for the illegal actions of their patrons.

“The act of making one person criminally liable for an act that they did not participate in is just not found in American jurisprudence,” Owen said.

Under the city’s ban, business owners can be cited for violating the law if a patron in their establishment is caught smoking. Among the changes made to the ordinance Tuesday were clarifications about when a business owner could be prosecuted under the law. Essentially, the new ordinance will allow business owners to be charged if they knew a person was smoking but acquiesced to the activity.

The new ordinance also allows employees to smoke in company-owned vehicles. The current ordinance bans that activity. City staff members said the change was needed to improve the enforceability of the ordinance.

But Owen argued that it was an exception that would violate the equal protection clause of the Constitution. He said a previously granted exception to allow Hallmark to keep a specially-ventilated break room for employees also made the ordinance unconstitutional.

He said commissioners should allow businesses, including bars and restaurants, to create similar specially-ventilated rooms where patrons could smoke.

City commissioners, though, did not waver in their support for the ban, which began in July 2004. Mayor Boog Highberger said the idea of allowing bars and restaurants to build specially-ventilated rooms was not feasible.

“It would be absolutely impossible to enforce,” Highberger said.

Highberger also said he felt nonsmokers could deal with the issue of smoking in company vehicles by simply asking fellow passengers to refrain from smoking while they are in a company car.

Commissioners also heard from supporters of the ban who urged that it be kept intact because it was improving the health of the community.

“Don’t forget that this is a public health issue,” said Dr. Steven Bruner, who also urged commissioners to keep the provision that bans smoking in company vehicles.

The city currently faces a lawsuit from Lawrence nightclub owner Dennis Steffes, who alleges that the ban is unconstitutional. Staff attorneys for the city told commissioners Tuesday night that they had reviewed many other smoking ban ordinances and believed Lawrence’s would pass constitutional muster.