PHNOM PENH (Reuters) - Doves flew into the sky and traditional dancers performed at huge rallies in the Cambodian capital of Phnom Penh on Saturday, as the ruling party of long-serving Prime Minister Hun Sen launched campaigning for general elections on July 29.

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Western countries and the United Nations have expressed concern the vote might not be free or fair after a court last year dissolved the main opposition Cambodia National Rescue Party (CNRP) for allegedly plotting to overthrow the government.

Most of the CNRP’s leaders have fled abroad, fearing a crackdown by Hun Sen and his allies on critics, including independent media and opposition lawmakers.

Hun Sen launched the campaign at a rally featuring traditional dance performances and doves and balloons released into the sky that drew about 60,000 supporters.

“If you love peace and development, please vote for the Cambodian People’s Party (CPP),” he said, to applause from the crowd, seated on plastic chairs.

Open criticism of Hun Sen has been muted in recent months following the crackdown. Several smaller parties also held rallies but none as big as that of the ruling party, which last week began to put up posters urging votes for Hun Sen.

In a speech lasting more than an hour, Hun Sen, who has been in power for 33 years, said his party had protected people and prevented the return of the genocidal Khmer Rouge regime that killed an estimated 1.7 million people in the 1970s.

“The CPP has been the only political force that has stayed and shared ups and down with the people, and has done everything for the interest of the people,” he added.

Hun Sen promised to increase wages for factory workers, civil servants and armed forces every year.

Analysts say Hun Sen is almost certain to win the election in the absence of the main opposition CNRP, dissolved by the Supreme Court last November after being found guilty of trying to overthrow the government with American help.

Both the CNRP and the United States have denied the accusation.

The dissolution followed the arrest of CNRP leader Kem Sokha.

Mu Sochua, deputy president of the now-dissolved CNRP, said it planned demonstrations in major Asian cities to denounce the election.

“Hun Sen is running alone, but still scared of defeat,” she told Reuters. “The question of illegitimacy is what he needs to deal with inside and outside the country.”