Sen. John Marty and two colleagues introduced legislation Thursday outlining the safeguards he believes are necessary if sports betting is legalized in Minnesota.

Bills to legalize sports betting on mobile devices have advanced in both the House and Senate, but neither has gotten a floor vote and the prospects remain uncertain. Marty is wary of the proposition and said if the state is going to expand gambling access, then it needs to provide protections for problem gamblers.

"I think, five years from now, we're going to have a lot of second thoughts," said Marty, DFL-Roseville, about expanding gambling to mobile sports betting.

Signing onto his bill as co-sponsors were DFL Sens. Scott Dibble of Minneapolis and Erin Maye Quade of Apple Valley.

Sen. Matt Klein, DFL-Mendota Heights, is sponsoring the main sports betting bill under consideration. While he didn't address the specifics of the new bill, he said he was pleased that Marty is looking at options.

"I'm encouraged that he has proactive ideas about how to legalize sports wagering safely in our state and isn't simply a hard no on the concept," Klein said.

Marty's ideas might sound like long shots, but few options can be discounted as a possible bargaining point. Given Democrats' narrow control of the Senate — with 34 votes, compared to Republicans' 33 — bipartisan support will likely be needed for something to pass.

Marty said he's open to discussion. When asked if his bill was an all-or-nothing proposition, Marty said: "Every bill gets negotiated, but I think this spells out the type of safeguards we ought to have."

Among his proposals are bans on betting on college sports and actions during games, known as prop bets. The bill would also ban gambling platforms from sending push notifications to users when their phones are idled.

Marty's bill also proposes a 40% minimum tax rate. He noted that New York's rate is 51%, negotiated with the gambling platforms. He would use a quarter of the tax revenue for schools to spend on mental health and addiction prevention.

Marty's stated goal is to try to prevent problem gambling from "predatory corporate sports books" that can try to attract consumers 24/7 on their phones. "This drives many recreational gamblers into problem gambling, where they spend money they don't have or cannot afford to lose," he said.

Other states have seen a tripling of calls to problem gambling hotlines after legalizing sports betting, Marty noted.

"The unfortunate reality is that gambling addiction has a higher risk of suicide than any other addiction," he said in his news release. "Half of the people in treatment have considered suicide. One in six have attempted suicide. That's a huge public health problem."

Even with the restrictions, Marty said Minnesota's mobile sports betting would be more widely accessible than neighboring states because three of the four states require gamblers to bet in casinos, not on their mobile devices.

What Marty's bill doesn't have: money for the two horse racing tracks Canterbury Park and Running Aces which is considered necessary to win GOP support.

"I don't think taxpayers should be subsidizing gambling operations, period," Marty said, adding: "When the tracks came in, they were going to generate lots of revenue for the state. And now, they're saying we've got to subsidize them with public money."