Disqualification means the ruling Cambodian People’s Party under Hun Sen is likely to sweep the election as it did in 2018.

Cambodia’s election commission has disqualified the Candlelight Party, the country’s main opposition party, from contesting July’s election in a move that will allow the ruling Cambodian People’s Party (CPP) to run virtually unopposed.

The commission said the party had failed to submit “proper registration documents”.

Other parties have signed up for the general election, but Candlelight was by far the most serious challenger to the CPP and Prime Minister Hun Sen’s decades-long grip on power.

“The Hun Sen regime once again shows its utter disdain for the principles of democracy and unwillingness to compete in free and fair elections,” ASEAN Parliamentarians for Human Rights board member Kasit Piromya, a former Thai foreign minister, said in a statement on Tuesday.

“If it wants the world to take the results of the July election seriously, the Cambodian government must halt all efforts to hamstring its opponents and ensure a space for all parties to participate.”

The move against the Candlelight Party echoes the ban on the opposition Cambodian National Rescue Party (CNRP) ahead of the last election in 2018, which allowed the CPP to win every seat in parliament. The Candlelight Party was previously the Sam Rainsy Party and joined forces with the Human Rights Party to form the CNRP in 2012.

Following Candlelight’s disqualification, CPP spokesperson Sok Eysan said the election would be free and fair and that more than 10 parties had registered.

Hun Sen has previously said the CPP will dominate Cambodian politics for up to 100 years.

Dozens of former CNRP members have been detained or convicted of crimes, many in absentia having fled into exile amid Hun Sen’s continuing crackdown on political rivals.

The election commission has demanded the Candlelight Party submit its original registration document from the Ministry of Interior in order to register for the election.

That document was lost when the police raided the CNRP headquarters in 2017, and it has taken part in subsequent polls by submitting a photocopy of the letter.

Candlelight Deputy President Son Chhay said Candlelight would appeal to the constitutional court.

“We have one week to do so,” he told the Reuters news agency in a text message.

Human Rights Watch last month accused Cambodia’s government of stepping up attacks on the opposition with rhetoric that had led to assaults on Candlelight members.

It took aim at Hun Sen for what it said were warnings against criticising his government ahead of the election.

In an April 24 statement, it said foreign governments should send a clear message that “dismantling opposition parties and disqualifying, assaulting, and arresting their members before election day means that there won’t be any real election at all”.

The government has denied it is targeting its opponents, saying legal cases were enforcement of the law.