DENVER — Colorado’s governor on Monday vetoed a bill to allow marijuana retailers to set up “tasting rooms,” dashing hopes that the state would be the first to adopt a system letting consumers use marijuana in public spaces.

Gov. John Hickenlooper has objected to similar bills in the past, arguing it could prompt a federal crackdown. He stayed quiet on the issue during the legislative session this year but wasn’t satisfied with the scaled-back proposal.

In a letter explaining the veto, Hickelooper wrote that the bill could have resulted in more impaired drivers on Colorado’s roads and other public health risks.

“We may agree with the proponents’ goals to protect the public and children; however, we strongly disagree that this bill is the correct path to achieve those goals,” he wrote.

This year’s proposal dramatically scaled back some advocates’ ambitions for stand-alone businesses reminiscent of a neighborhood bar or an upscale club where marijuana products would replace alcohol. The bill did not allow smoking of marijuana in the establishments and also let local municipalities decide whether to allow the so-called “tasting rooms.”

But some lawmakers publicly worried that step could draw the attention of federal authorities, including Attorney General Jeff Sessions.

Supporters hoped the narrow bill could resolve a stubborn conflict in Colorado and other states with legal marijuana – possession by adults is legal, but using it in public, including streets, parks and most hotels or rental properties, could lead to a citation.

Other states have repeatedly delayed or avoided a statewide system for public use, including Alaska, where regulators are expected to resume discussions this month on letting people consume inside retail stores.

In Maine, the legislation passed in April over the governor’s veto doesn’t allow for social clubs, even though they were permitted in the ballot question approved by voters in November 2016. That means adults who buy their cannabis in the state will have to consume it on private property, with the permission of the property owner.

In Denver, a voter-backed initiative forced regulators into allowing so-called “social consumption facilities” where customers bring their own marijuana. But state and local regulators’ tight controls on business models and permitted locations have limited interest.

Advocates denounced Hickenlooper’s veto Monday, arguing that it will allow unregulated indoor clubs to continue operating without legal authority.

“In its wisdom, the Colorado Legislature sought to close a significant gap in regulation,” said Chris Woods, the owner of Terrapin Care Station. “It’s unfortunate that the governor chose not to offer another regulatory tool to state and local regulators. This fight is not over.”