Las Vegas (AP) – Major Nevada casinos have filed a district court brief opposing efforts to prevent southern Nevada police and prosecutors from enforcing a voter-approved statewide smoking ban.

Attorneys for the Nevada Resort Association, which represents most major hotel-casinos in the state, say the group’s intervention is necessary because of the legal tack taken by southern Nevada business owners fighting the smoking ban.

The dispute over terms of the Nevada Clean Indoor Air Act is scheduled for a hearing Tuesday before Clark County District Court Judge Douglas Herndon.

In the legal brief filed Friday, resort association attorneys asked for a ruling against taverns, slot machine route operators and other businesses that oppose the ban, and also for a finding that the ban does not apply to hotel and motel rooms.

The resort association also wants a finding that the ban doesn’t unfairly distinguish between the major clubs that hold nonrestricted gambling licenses and smaller operators with restricted licenses, typically for slot machines.

The Clean Indoor Air Act, approved as Question 5 on the Nov. 7 ballotby a 54-46 percent margin, would ban smoking in bars that serve meals; in slot machine sections of grocery and convenience stores; and at video arcades, shopping malls, schools and day-care centers.

It would allow smoking in the gambling areas of casinos.

The business group filed suit asking for an injunction and a restraining order to keep law enforcement officials from enforcing the law, claiming it was unconstitutional, too vague to comply with, and unfairly discriminated against some businesses.

Business owners were joined in the case by the Nevada Association of Tavern Owners, bringing the number of plaintiffs seeking to challenge the ban to more than 220 establishments.