PHNOM PENH (Reuters) - Cambodian opposition leader Sam Rainsy was fined in absentia on Tuesday for accusing Prime Minister Hun Sen of having fake Facebook page “likes”, the latest government case against the opposition before a general election in 2018.

Cambodian opposition leader Sam Rainsy delivers a speech to members of the Cambodia National Rescue Party (CNRP) at a hotel in metro Manila, Philippines June 29, 2016. REUTERS/Romeo Ranoco

Hun Sen is taking a belated leap into the digital age in a bid to court young, urban voters ahead of the election, tipped to be the biggest test of his three-decade rule.

Hun Sen’s Facebook page has surged to over six million likes, comparing to Sam Rainsy’s 3.3 million, after he embraced the platform following almost losing a 2013 election when the opposition Cambodia National Rescue Party (CNRP) won a surge of support online.

The Phnom Penh Municipal Court found exiled CNRP president Sam Rainsy guilty of defamation over his social media post in March accusing a ruling party senior official of ordering civil servants to boost Hun Sen’s Facebook page “likes” by creating fake accounts.

The court ordered Sam Rainsy to pay a total of $6,250 in fines and compensation.

Som Soeun, a government official who handles Hun Sen’s Facebook page, said that Sam Rainsy was embarrassed after his rival’s surge in likes so he had made up the allegation.

“This is like a competition,” Som Soeun told reporters. “When he lost, he cried foul.”

Sam Rainsy’s lawyer said the opposition planned to appeal.

Tension between Cambodia’s two main political parties, Hun Sen’s Cambodian People’s Party and the CNRP, has risen in recent months, with the opposition complaining of a crackdown in a bid to intimidate critics before the election.

The court jailed an opposition senator on Monday for seven years over his Facebook posting of a fake government pledge to dissolve the border with Vietnam, a verdict opposition members say could fuel tension in the Southeast Asian nation.