Members of a Cambodian conservation group are facing up to 10 years in prison on charges its founder says are politically motivated and part of a wider crackdown on government criticism - allegations authorities deny.

Ten activists from the Mother Nature group have been accused of plotting against the government, charges that carry a maximum penalty of 10 years in jail. Three are also charged with violating Cambodia's lese majeste laws, which carries a maximum five-year sentence, with the court expected to deliver verdicts on Tuesday.

The proceedings come amid deepening concern about political freedom in Cambodia under Prime Minister Hun Manet, who took power last year after the decades long rule of his father, Hun Sen. Under Hun Sen, the opposition was all but dismantled, independent media shuttered and dozens of activists jailed.

Facing the charges in absentia, Mother Nature founder Alejandro Gonzales-Davidson has slammed the trial.

"It's a kangaroo trial," he said, adding his lawyer had said there was no evidence to support the charges.

Pen Bona, a spokesperson for the Cambodian government, denied the group was being targeted for its environmental activism or that the charges were politically motivated.

"The government has never taken action against those who criticize. The government only takes action against those who commit crimes," he said.

Founded by Spanish national Gonzales-Davidson in 2013, Mother Nature has long campaigned against environmental destruction in Cambodia, highlighting deforestation, illegal sand mining and corruption in development projects.

Three activists involved in the trial have previously been jailed on incitement charges but have since been released.

The most recent charges had been dormant since 2020 but were revived in May, said Gonzalez-Davidson, who was deported almost a decade ago and is banned from re-entering the country.

The accusations of plotting against the state had not been clarified in court, he said, but three members were arrested after documenting suspected pollution run-off into the Tonle Sap River in Phnom Penh in 2021.

The lese majeste charges relate to an internal Zoom meeting about political cartooning that was leaked.

The activists have denied any wrongdoing, while Human Rights Watch (HRW) has called on the government to drop what it says is a case "intended to muzzle criticism of government policies".

"Cambodian Prime Minister Hun Manet, like his father, Hun Sen, seems intent on jailing environmental activists instead of embracing their contribution to Cambodian society," said HRW's Bryony Lau.

  - Reuters