Signs warning against the sale of tobacco to minors are displayed in the window of a Lawrence store, Thursday, Feb. 11, 2016.

Topeka ? Cities and counties may use their home rule authority to enact local laws prohibiting the sale of cigarettes and other tobacco products to people under age 21, Attorney General Derek Schmidt’s office said Thursday.

In a formal attorney general’s opinion, Schmidt’s office said such local laws do not conflict with state law, which sets the minimum age at 18, because they do not allow the sale of tobacco products to people younger than 18. The local laws only go further than state law.

The opinion was issued at the request of Senate Vice President Jeff Longbine, R-Emporia.

“We also note that there is no statute that expressly authorizes persons at least 18 years of age to purchase cigarettes or tobacco products, so an ordinance or resolution such as you describe would not forbid that which a state statute authorizes,” the opinion states.

So far, 19 cities and counties in Kansas have enacted local laws raising the minimum age for buying tobacco products to 21. The most recent was the city of Topeka, which gave final passage to its ordinance on Dec. 5.

So far, neither Lawrence nor Douglas County has joined the movement, but some local health advocacy groups recently formed what they’re calling the Tobacco 21 Task Force, which recently held a public forum to organize support for such an effort.

Those efforts are part of a national movement called Tobacco 21, a project of the Preventing Tobacco Addiction Foundation that began in 1996.

In Kansas, attorney general’s opinions are not law, and they can be reversed by courts. But courts generally give them some deference, and they offer government entities some protection from lawsuits because they enable those entities to argue that their actions were based on the advice of counsel.

The opinion points out that Article 12, Section 5, of the Kansas Constitution gives cities authority “to determine their local affairs and government,” a power commonly referred to as “home rule.”

Counties have similar authority under a state statute that says they have the power “to exercise the powers of home rule to determine their local affairs and government.”

In recent years, Kansas lawmakers have passed legislation that cities and counties argue chips away at their home rule authority by prohibiting local governments from taking certain actions in areas such as gun control, minimum wage requirements and raising property taxes.

The attorney general’s opinion on limiting tobacco sales, however, could stymie any efforts in the 2018 session to take away that authority.