TALLAHASSEE — As behind-the-scenes negotiations broke down in the final hours of their annual session Friday, the Florida Legislature failed to pass legislation putting medical marijuana, passed overwhelmingly by voters, into effect.

A dispute over technical parts of the bill became too much for negotiators to overcome. At issue were restrictions on growers and dispensaries, a topic important to those who wanted a piece of what experts say could become a $1 billion a year market.

It now falls to the Florida Department of Health to write rules by July 3 that will allow patients with debilitating illnesses to legally use to medical marijuana.

"If I were a voter I would be very disappointed," said Ray Rodrigues, R-Estero, who sponsored the House bill to legalize the drug. "They had a legitimate expectation that we would pass an implementing bill."

Not passing a bill "thwarted" the voters, said Ben Pollara, executive director of Florida for Care and the campaign manager of the campaign for Amendment 2.

"The Florida Legislature chose political gamesmanship over the will of 71 percent of voters," he said in a statement. "The House got to poke the Senate in the eye one last time, but the real losers are sick and suffering Floridians."

The Legislature will be back in Tallahassee on Monday to pass the state budget, but the resolution lawmakers passed to extend session by three days doesn't allow them to consider medical marijuana.

The Department of Health has two months to turn placeholder rules it published in January into a thriving medical marijuana market that could grow to hundreds of thousands of patients.

Department of Health officials held five public hearings around the state, but they appeared to be waiting for lawmakers to act. "We welcome that," Christian Bax, who runs the department's medical marijuana office, told lawmakers in January.

The Department of Health rules essentially gave the whole medical marijuana marketplace to the seven growers who have already been licensed to sell low-THC cannabis to patients with severe epilepsy and cancer and full-strength marijuana to terminal patients.

"It would have been preferable for the Legislature to be the one to set the basic framework for how it's implemented," said Senate President Joe Negron, R-Stuart. "In the absence of that, I think we'll have to rely on the Department of Health to implement it in a fair way, to make sure that there's access."

Handing over control to the Department of Health, however, concerned other lawmakers.

"We will be stuck with a situation where the Department of Health has to implement Amendment 2, which would be disastrous for patients," said Rep. Carlos Guillermo Smith, D-Orlando.

House and Senate leaders, who for weeks had described their talks as productive, haggled all week. By midday Friday, they were describing the odds of passing a bill as "50/50" and "a toss-up."

The problem? A cap on the number of dispensaries each licensed-company can open.

A plan passed by the Senate on Thursday would have let each grower open five dispensaries to start, plus one more for every 75,000 patients in the state. Setting caps, as other states have, would allow for newly licensed growers to gain a foothold, argued Sen. Rob Bradley, R-Fleming Island, who sponsored marijuana legislation in the Senate.

The House, meanwhile, wanted no caps.

"Just because you're first in market doesn't mean you own the market," Rodrigues said. "If someone comes along and their product is better, I believe the free market will work and quality will rise to top, and the public will respond to that."

Friday night that chamber put a cap at 100 dispensaries per grower. Senators didn't consider the bill again.

"We're not in at 50," said Sen. Bill Galvano, R-Bradenton, who was involved in the negotiations.

Both House Speaker Richard Corcoran, R-Land O'Lakes, and Negron, the Senate president, said early in the year that they wanted to make sure the Legislature had its say on medical marijuana.

And for months, Rodrigues framed the issue as a must-pass for the Legislature. If they didn't act, he warned, the issue would likely be decided in the courts. On Friday, he tried to shift the blame for the Legislature's failure to pass a bill squarely on the Senate.

"We have until midnight," he said. "If the Senate can't get this bill heard and decided in the next 3.5 hours, that problem's with them, not with us."

Then, the House sent the medical marijuana legislation — with the language senators didn't want — back to the Senate, and both chambers adjourned for the weekend, killing the bill.

Contact Michael Auslen at mauslen@tampabay.com. Follow @MichaelAuslen.