Updated

Political leaders from Mexico's main heroin-producing state are pushing the federal government to legalize opium production for pharmaceutical use in a move they hope will reduce violence and help local farmers.

Legislators in Guerrero state voted Friday to send an initiative to the Mexican Senate for further debate, since the proposal to legitimize opium output would require changes to federal health and penal codes.

Incoming Interior Minister Olga Sanchez has expressed support for nationwide legalization of opium production for medical purposes after President-elect Andres Manuel Lopez Obrador takes office in December.

The mountainous state of Guerrero, on Mexico's southern Pacific Coast, is home to most of the poppy bulbs that yield heroin consumed in the U.S.

Guerrero state legislator Ricardo Mejia said an estimated 120,000 people cultivate poppy in poor, isolated communities across the state. A legal channel to sell sticky poppy sap could offer growers more stable incomes, he argues.

The United Nations estimates that Mexico has the world's third-largest geographic area dedicated to illicit opium cultivation, after top producer Afghanistan and Myanmar. Yet prescription opioids are severely restricted for cancer patients and the terminally ill in Mexico.

"We propose a paradigm change," Mejia said.

Criminal groups control access to the poppy fields tucked high in the rugged Sierra Madre mountains of Guerrero, more than five hours by car along bumpy dirt roads from the state capital of Chilpancingo or the nearby beach resort of Acapulco. Subsistence farmers have been pressured under threat of violence in recent decades to grow poppy rather than crops like coffee or mangoes.

Mejia considers the forced production of poppy a form of slavery.

"They can recover their freedom via the legal cultivation of poppy," he said. "Right now the criminal groups have a social base because they control the only economic activity of the people."

Guerrero Gov. Hector Astudillo first floated the idea of decriminalizing poppy in 2016 to combat the state's rampant drug gang violence. Guerrero has one of the highest murder rates in Mexico, with 71 homicides per 100,000 residents last year.

The lush green hills of Guerrero are ideal for poppies. Mountains shield the delicate plant from strong winds, while high elevations and an arid climate prevent moisture from sucking away its precious sap. At harvest, growers slice the bulbs, releasing sap with a high morphine content. The sap forms a paste that is then scraped off and sent for processing in clandestine labs.

But this lucrative industry is under threat. Guerrero state security spokesman Roberto Alvarez says increased use in the U.S. of synthetic opioids such as fentanyl has caused prices for Mexican opium paste on the black market to plummet to as little as $263 per kilo from more than $1,000 per kilo a year ago.

Criminal groups have compensated for the lost revenue by ramping up extortions, vehicle thefts and kidnappings in Guerrero, while subsistence farmers struggle to make ends meet.

"The growers are in a crisis situation," Alvarez said. "Opium used to be a very good income — enough to buy a TV or a little car and to get by. Now it's not viable."