Mexico’s president Enrique Peña Nieto has announced plans to introduced laws to legalise medical marijuana and increase the quantity anyone can carry and consume for recreational purposes from five grams to 28 grams. His plan would also free some prisoners convicted of possessing small amounts of marijuana.

The proposed laws, he said on Thursday, would stop “criminalising consumption” and also authorise the use of medicines made from a base of marijuana and or its active ingredients.

The initiative, which will now go to the senate for debate, signals a shift for Peña Nieto, who says he has never smoked marijuana and has openly opposed its legalisation.

It follows his announcement earlier this week at the United Nations General Assembly Special Session on drugs, UNgass, in which Peña Nieto called for more prevention, partial decriminalization and a public health approach.

Although Mexico – along with Colombia and Guatemala – had lobbied the UN to bring forward the special session from its original date of 2018, Peña Nieto had originally planned to skip the meeting. He made a U-turn under criticism at home. Mexico, which sees enormous shipments of drugs smuggled through its territory to the US, has been hit hard by violence stemming from a 10-year crackdown on drug cartels and organised crime that has claimed more than 100,000 lives.

Medical marijuana made national news in Mexico last summer after the parents of an eight-year-old named Graciela Elizalde won the right to use a medicine containing cannabinoids to treat Lennox-Gastaut syndrome, a condition causing hundreds of daily epileptic seizures.

In November, the supreme court also granted injunctions to four individualsseeking permission to cultivate and consume marijuana for recreational reasons – a move that activists believe paves the way to broader decriminalisation.

Peña Nieto strongly opposed the ruling but responded by proposing a series of five forums on the drugs issue. Those results were released Monday and included prevention, facilitating the medical use and investigation of controlled substances and dealing with drugs “from a perspective of human rights”.

Polls show Mexicans are mostly opposed to medical marijuana, though opposition has softened over the past six months. Polling firm Parametría found 71% of Mexicans are opposed to recreational marijuana, though 64% approved using it for medicinal purposes.

The president’s initiative on medical marijuana comes as Mexico’s record on human rights has been questioned and Peña Nieto’s approval rating reaches record lows.

Security analyst Jorge Kawas saw the measure sparing some individuals the indignity of the problematic Mexican justice system, but doing nothing “with the supply side of the equation.”

He added, “I see [drug legalization] as almost a non issue” in Mexico’s domestic politics, though “it could give some positive press abroad and at the same time provide some important front-page space in the national papers.”