The Jamaican cabinet has approved a bill that would decriminalise possession of small amounts of cannabis and pave the way for a legal medical marijuana industry, the justice minister has said.

Mark Golding said he expected to introduce the legislation in the Senate this week. Debate could start this month in the country where the drug, known popularly as “ganja”, has long been culturally entrenched but illegal.

The bill would establish a cannabis licensing authority to deal with the regulations needed to cultivate, sell and distribute the herb for medical, scientific and therapeutic purposes. “We need to position ourselves to take advantage of the significant economic opportunities offered by this emerging industry,” he said.

It would make possession of 2 ounces (56g) or less an offence that would not result in a criminal record. Cultivation of five or fewer plants on any premises would be permitted. Rastafarians, who use marijuana as a sacrament, could also legally use it for religious purposes for the first time in Jamaica, where the spiritual movement was founded in the 1930s.

For decades, debate has raged on the Caribbean island over laws governing marijuana use. But now, with several countries and US states relaxing their laws on the herb, Jamaica is advancing reform plans.

Golding said the government would not soften its stance on drug trafficking and it intended to use a proportion of revenues from its licensing authority to support a public education campaign to discourage pot-smoking by young people and mitigate public health consequences.

The director of the national Cannabis Commercial and Medicinal Research Taskforce said he expected the bill to be passed soon in parliament, where Portia Simpson Miller’s governing party holds a 2-1 majority. “This development is long overdue,” Delano Seiveright said.