Topeka ? A tense legislative stand-off over a statewide indoor smoking ban may erupt next week.

House Democratic Leader Paul Davis of Lawrence said Friday that supporters of a ban may try to override a proposal in a House committee that contains numerous exemptions that would allow smoking in public, indoor places.

To do that, supporters of a ban will try to pass a motion in the House to concur with a tougher ban that has already been approved in the Senate.

“The votes are very close,” in the 125-member House, Davis said.

Davis said supporters of a ban have become concerned over the “watered down” House bill.

House Bill 2642 would allow businesses, such as restaurants and bars, to allow indoor smoking if they had separate ventilation systems for smoking sections and paid a nominal fee. Clean air advocates say the bill also would overturn more than 30 local ordinances that have tighter restrictions, including the one in Lawrence.

The Senate bill would ban indoor smoking. But supporters of the House bill oppose a provision in the Senate bill that would allow smoking in state-owned casinos. They say that’s unfair to private businesses.

Gov. Mark Parkinson has said that he’s not crazy about the casino provision but said the Senate bill is far superior to the House bill, which he called a “fraud” and said he would veto.