The government’s move to reclassify cannabis as a narcotic threatens to trigger street protests and lawsuits by owners of thousands of dispensaries that have sprung up across the country since decriminalisation two years ago.

A complete re-criminalisation ordered by Prime Minister Srettha Thavisin on Wednesday will also push the cannabis trade underground, said Rattapon Sanrak, owner of the Bangkok-based dispensary Highland Cafe.

Thailand’s Cannabis Future, an advocacy group, said it would hold a protest against the move in Bangkok on May 16.

Cannabis currently enjoys the status of a “controlled herb” and there is no outright ban on its recreational use, which has allowed nearly 8,000 dispensaries to open since it was removed from the narcotics list in June 2022.

Mr Srettha’s plan to re-label cannabis as a Category 5 narcotic will make it a crime to “produce, sell, import, export or possess” the plant and use it, according to drug laws.

Cannabis for medical and health purposes would still be allowed, according to the PM.

“We’re all doing everything by the book but then suddenly the book is going to change,” Mr Rattapon said. “We’re gearing up to protest and preparing to file lawsuits in the event it happens.”

The policy U-turn is another blow to the country’s cannabis industry after decriminalisation was pitched as a way to boost agricultural income and wellness tourism.

The Bhumjaithai Party, which spearheaded decriminalisation, said a bill to regulate recreational use would be more effective than outlawing the plant entirely.

The most recent attempt under the Srettha government to outlaw recreational use has been stalled by the bureaucratic process. A change in ministers last week could lead to further delays.

Cannabis advocates are urging health authorities to weigh the pros and cons of cannabis in comparison to alcohol and cigarettes and use science and facts to determine what should be drugs.

“Instead of regulating the industry properly, you’re choosing to close it up and make it worse by pushing it underground,” Mr Rattapon said.