INDIANAPOLIS — Legislative leaders are leery of a proposal backed by the Indiana Chamber of Commerce to raise the state’s legal age for buying cigarettes from 18 to 21.

The statewide business group announced a lobbying agenda Monday for the legislative session that starts in early January, saying Indiana needs to reduce its smoking rate that causes an estimated $3 billion in annual heath care costs in the state. The chamber also is calling on the Republican-dominated Legislature to repeal a state law that prohibits businesses from refusing to hire tobacco users.

Republican House Speaker Brian Bosma said he expected many libertarian-leaning GOP House member would have trouble taking those steps.

“I have a bit of difficulty telling somebody that they can go to Iraq and fight for freedom but they can’t buy a pack of cigarettes,” Bosma said. “I get that we do something different with alcohol in that regard.”

Proposals for a $1-per-pack increase in Indiana’s current 99-cent cigarette tax have cleared the House the past two years but failed to win approval in the Senate. Such a tax hike is unlikely to be debated next year as lawmakers aren’t expected to consider major budget issues.

Cigarette makers opposed the tax hike, arguing it would drive consumers to neighboring states with lower prices.

But public health advocates said it would have provided a powerful disincentive to quit or to never start smoking and result in additional revenue for health care and smoking cessation programs that have had funding slashed over the past 15 years.

Indiana has the 12th highest smoking rate in the nation among states, according to the United Health Foundation’s 2016 report. Indiana’s 20.6 percent smoking rate topped the national rate of 17.5 percent.

Three states — California, Hawaii and New Jersey — now require anyone buying cigarettes to be 21, while similar laws take effect next year in Oregon and Maine. Indiana is among 19 states that prohibit local governments from setting higher ages for tobacco use, according to the Preventing Tobacco Addiction Foundation.

Republican Senate majority leader Brandt Hershman said he believed raising Indiana’s tobacco age was a worthy discussion topic given the state’s cigarette troubles, but didn’t know whether state government should go that far.

“People know they are doing something that they shouldn’t,” Hershman said of smokers. “I just look at government intrusion with a little bit of a cautious eye.”