By Prak Chan Thul
PHNOM PENH, July 26 (Reuters) - Cambodia's political parties hit the streets on Friday in a final push for votes in Sunday's general election, but a rights group said the campaign had been biased in favour of Prime Minister Hun Sen's party, widely expected to retain power.
Hun Sen has been premier for 28 years, bringing stability after years of war and the genocidal late-1970s regime of the Khmer Rouge but, his critics say, he has shown disdain for democracy through intimidation of opponents and electoral fraud.
In a statement on Friday, U.S.-based Human Rights Watch listed a series of problems that had marred the campaign, which officially ends at midnight on Friday.
Among the problems it found were unequal access to media for the opposition, the manipulation of voters lists and campaigning by officers of the security forces for the ruling Cambodian People's Party (CPP).
"The entire process is biased in favour of the ruling party and against the opposition. What should result in the will of the people has been organised to result in the will of the Cambodian People's Party," said Brad Adams, its Asia director.
He noted opposition leader Sam Rainsy had been allowed home from self-exile after a royal pardon removed the threat of a jail sentence, but the electoral authority had still ruled he could not run in the election or even vote.
"An election with the leader of the opposition banned on spurious grounds is almost the definition of an unfair and undemocratic process," he said.
Sam Rainsy's eponymous party merged with another last year to form the Cambodia National Rescue Party (CNRP). It is hoping to improve on the 29 seats the two parties held in the outgoing parliament. The CPP had 90 of the 123 seats.
"People here are sending a message to the current leaders that it's time for them to step down," Sam Rainsy told supporters in a Phnom Penh park.
"They should be ashamed of themselves and leave before they are chased out."
LAND AND MIGRANTS
His party has promised to increase wages in the garment sector - Cambodia's main export earner, built on low pay - and provide free health care for the elderly.
Sam Rainsy, a former finance minister, said he would also put an end to "land grabs" in the countryside, where allies of Hun Sen and some foreign companies have been accused of stealing land from farmers.
"We will claim back our land and rivers, there won't be anymore 80- or 99-year leases for economic land or concessions for mining," he said.
Another party leader, Yim Sovann, said the CNRP would halt what he called an influx of illegal Vietnamese immigrants. The issue of migrants from Vietnam is an emotive one in Cambodia where many people harbour suspicion of their much-bigger neighbour.
Hun Sen and his CPP rose to power with the help of the Vietnamese army which invaded in late 1978 to oust the Khmer Rouge and then occupied Cambodia for the next decade.
"We must be united to replace the corrupt dictator this Sunday," Yim Sovann said. "The CNRP wins, everybody wins."
Elsewhere in the capital, an estimated 40,000 people joined a rally for the CPP, whose frail-looking leader, Chea Sim, appeared briefly but did not speak.
Kep Chuktema, a CPP candidate for Phnom Penh, thanked his supporters for putting up with attacks by the CNRP. "Though there were insults in an attempt to drive a division between the people and the CPP, they could not succeed," he said.
(Writing by Alan Raybould; Editing by Robert Birsel)