Cambodia’s long-term leader is almost certain to extend his party’s rule at an election on Sunday where there no serious challengers.

Voters turning up to the polls in Phnom Penh told the BBC they expected the Cambodian People’s Party to sweep all 125 seats in parliament again.

Hun Sen, who has been in power for 38 years, faces no real challenge after the only credible opposition party was disqualified in May.

Critics have called the vote a sham.

“It’s a rigged election because there are no real strong opposition parties,” one voter, an aid worker in Phnom Penh, told the BBC earlier this week.

Western nations, including the US, have also expressed concerns about the integrity of the vote.

Opposition lawmakers this year have reported violent attacks, with Human Rights Watch reporting the government stepped up intimidation and arbitrary arrests of political opposition in the run-up to the poll.

In May, the government barred the country’s main opposition party, the Candlelight Party, on a technicality. The National Election Commission said the party was missing paperwork, which it had not needed for the local elections last year.

Candlelight had won 22% of the vote last year – and analysts say Hun Sen saw them as a potential threat to his rule.

Hun Sen has become increasingly authoritarian in his rule, political analysts say.

Earlier this year, leading opposition figure Kem Sokha was sentenced to 27 years prison on alleged treason charges, and key news outlet Voice of Democracy shut down.

It is the second election in a row where Hun Sen has targeted democratic institutions and crippled the opposition before voting day, analysts say.

In 2018, his Cambodian People’s Party won every single seat in the 125-seat National Assembly after the main opposition alliance was dissolved by the politically- controlled courts.

Seventeen other parties are participating in this year’s election, but almost all are too small, new or are aligned with the ruling party to be considered credible challengers.

The vote comes at an uncertain time for Cambodia’s economy – with locals reporting struggles with rising fuel prices, stagnant wages and growing debts.

While Hun Sen is campaigning for re-election, he has flagged that this may be his last term. In 2021, he said would hand over control to his eldest son who currently commands the Royal Cambodian Army.

Han Manet is a first-time candidate for a parliament seat this election and led the final day of party rallies in Phnom Penh on Friday.

However it’s unclear if of when his father will relinquish control.

Hun Sen’s party has won all six of the national elections held every five years since the 1990s, when the UN helped the Southeast Asian nation of 16 million people become a functioning democracy post decades of civil war and the murderous Khmer Rouge regime.

Over four decades, he has consolidated power through control of the military, police and moneyed interests. Observers say he has dispatched opponents through co-opting, jailing or exiling them.