By Dave Graham
MEXICO CITY (Reuters) - A national debate on overhauling Mexico's marijuana legislation will consider easing custodial sentences and raising the amount of the drug that people can carry, according to the government official tasked with overseeing the process.
Deputy Interior Minister Roberto Campa told Reuters in an interview that the consultation process kick-started by a Supreme Court ruling last week aimed to present its conclusions by early April and help legislators take the next steps.
Reviewing a challenge to existing laws, the court ruled that a group of four people should be able to cultivate and consume their own marijuana, opening the door to change in the law in a country long battered by drug cartel violence.
The court decision was quickly followed by a Senate proposal from within President Enrique Pena Nieto's Institutional Revolutionary Party to legalize medicinal use of marijuana, which appears to have substantial cross-party support.
However, the consultation process due to run from January to March will take a wider view of marijuana policy and its impact on the criminal justice system, Campa said, careful to stress the government should not anticipate its outcome.
There was broad consensus among experts that there had been "abuse" of the state's power to incarcerate people, especially for drug offenses, he said.
"I hope that what follows allows many alternative mechanisms to imprisonment to be found, because experience shows that someone who goes to jail for something minor ends up back there after being let out - a sort of revolving door," he said.
A 2012 study by Mexican think tank CIDE found that just over 60 percent of the prison population - today about one quarter of a million people - was serving time for drug-related crimes, including eight out of 10 women inside.
Nearly 60 percent of those inmates said they were jailed for marijuana offenses, according to the study.
In 2009, Mexico decriminalized possession of up to 5 grams (0.18 ounce) of marijuana as well as tiny amounts of other drugs, and Campa said public health authorities believed it could make sense to raise the pot threshold.
U.S. states that have legalized recreational use of marijuana, including Washington, Colorado and Oregon, permit possession of at least an ounce (28 grams), he noted.
"We're well below that," Campa said.
The debate will also address a difficult issue left open by the Supreme Court - where anyone permitted to grow marijuana should acquire the seeds from, he added.
Polls in Mexico show a clear majority of the public is opposed to legalizing pot, Campa noted. But the reform debate is also taking place in the context of steps to liberalize policy in countries such as the United States, he added.
Voter surveys show California could next year join the ranks of states to legalize recreational marijuana usage, and Mexico will be paying close attention to events there.
"We can't ignore the relevance of the decisions in the United States, and we can't ignore the fact that a change in California will have very important implications in the United States and also in Mexico," said Campa.
(Editing by James Dalgleish)