PHNOM PENH, Cambodia (AP) -- Cambodia's Supreme Court ordered the main opposition party to be dissolved on Thursday, dealing a crushing blow to democratic aspirations in the increasingly oppressive Southeast Asian state. The decision clears the way for the nation's authoritarian leader to remain in power for years to come.

The verdict, which was widely expected, comes amid a growing push by the administration of Prime Minister Hun Sen to neutralize political opponents and silence critics ahead of elections due in July 2018.

Chief Judge Dith Munty, who is a senior ruling party member, announced the nine-member court's unanimous ruling. 

He said 118 opposition party members would also be banned from politics for the next five years.

The government accuses the Cambodia National Rescue Party of plotting a coup and has called for its dissolution for weeks. The opposition staunchly denies the allegations and says they are politically motivated -- a position backed by international rights groups and independent analysts who say no credible evidence has emerged to back the claims.

The party had been expected to pose a serious challenge in next year's polls. During the last vote in 2013, it scored major gains in a tense race that saw Hun Sen narrowly retain office.

Hun Sen has been in office since 1985 and has held a tight grip on power since ousting a co-prime minister in a bloody 1997 coup. 

Although Cambodia is a nominally a democratic state, its institutions remain fragile and the rule of law weak; the judiciary is not seen as independent.

Before Thursday's ruling, Hun Sen had encouraged opposition lawmakers to defect to his ruling party. In a speech last week to garment workers, he was so confident the court would rule against the opposition party that he offered anyone 100 to 1 odds if they were willing to bet it would not happen.