PHNOM PENH: Cambodia’s king brought Prime Minister Hun Sen face-to-face with the head of the opposition for the first time in years Saturday, urging the political rivals to find a peaceful solution to their post-election stalemate for the sake of national stability.

No agreement was reached at the brief meeting at the Royal Palace in Phnom Penh, but Hun Sen is expected to meet opposition leader Sam Rainsy again Monday for further talks, opposition officials said.

Sam Rainsy’s party says it would have won had the July vote been fair and has vowed to stage a new wave of protests Sunday unless an independent committee investigates its claims of widespread voting irregularities. The government has rejected the demands, and there are fears the protests could trigger violence.

As the two looked on, King Norodom Sihamoni read a statement saying he was “begging the leaders of the two parties to cooperate” to overcome their political differences in the interest of “maintaining peace and stability” in Cambodia.

Sihamoni urged all elected lawmakers to attend the opening session of parliament, which he will preside over on Sept. 23. The opposition has vowed to boycott the legislative session unless the dispute is resolved.

Saturday’s talks lasted about 20 minutes, and Hun Sen left without commenting. Asked by reporters what had come out of the meeting, Sam Rainsy replied simply: “No, no, there is nothing.”

Sam Rainsy’s party made major gains in the July vote, although the ruling party retained a majority of legislative seats. Official results ratified last weekend gave Hun Sen’s party 68 seats in the National Assembly and Sam Rainsy’s 55.

As the post-election standoff has dragged on, hopes had risen that Sihamoni could serve as a mediator, a role often played by his father. The late Norodom Sihanouk helped broker an end to civil war in 1991 and arrange power-sharing agreements after the 1993 and 2003 elections.

Sihamoni, who took over the throne in 2004, has so far taken a less active role. Hun Sen and Sam Rainsy both greeted Sihamoni at the capital’s airport Wednesday upon his return from China but did not acknowledge each other.

“The king is the only person right now who can get these two parties to meet and discuss all their differences,” opposition lawmaker Son Chhay said this week.

Ou Virak, president of the Cambodian Centre for Human Rights, said that the discussions could have focused on allotting the opposition several parliamentary leadership positions, reforming the electoral commission and allowing Sam Rainsy to take a seat in parliament.

Just before the disputed vote, Sihamoni pardoned the then self-exiled Sam Rainsy at the request of Hun Sen - likely under international pressure to legitimise the poll. He returned to Cambodia before the election, but too late to register as a candidate himself.

Their meeting comes a day before the opposition has planned another mass protest in Phnom Penh. Opposition leaders have said they expect 20,000 people to turn out again to demand an investigation into the election results. They say the protest will continue for three days.