For democracy torch-bearer Sam Rainsy and deposed former first prime minister Prince Norodom Ranariddh it presents little hope of reducing Mr Hun Sen's omnipotent grip on the wheel of power in Southeast Asia's poorest country.

Mr Hun Sen, recovering from an emergency appendix operation on Friday, has been keeping a low profile to protect a shaky popularity, apparently confident that a vast party machine in the countryside will make sure the vote swings his way.

For the public there is confusion and fear. City dwellers were yesterday starting to hoard rice and withdraw cash from banks.

Two soldiers escorting election workers were killed on Friday when their convoy delivering supplies was attacked by Khmer Rouge guerillas northeast of the one-time rebel stronghold of Anlong Veng near the Thai border, officials said.

Vietnamese shopkeepers were pulling down their grilles and keeping their children indoors amid speculation the borders could be shut.

The opposition has been far more vigorous as it intensifies speeches and rallies, but the options are far from black and white.

Amid all the problems facing Cambodia's fractured society and economy, it is the hatred of the Vietnamese that seems to unite the opposition against Mr Hun Sen, who was first installed by Hanoi's invading forces in 1979.

Prince Ranariddh is playing up his links to King Sihanouk to impress the peasants but, with Mr Sam Rainsy, he has whipped up racial hatreds with references to 'yuon' - a derogatory Khmer term for Vietnamese.

'If we vote for the right party, the yuon will leave; if we choose the wrong party, the yuon will be more,' Mr Sam Rainsy said.

In Pailin, Mr Sam Rainsy - a brave human rights campaigner with international respect - told a crowd of more than 5,000: 'This Government has ruled for 20 years.

'If it were democratic, it wouldn't last without the yuon behind them.

'They lost the 1993 elections but used force to keep power. Ranariddh was weak and was cheated by the yuon puppets.' Hanoi has voiced protests, increasingly shrill in the wake of the shootings on Tuesday of four ethnic Vietnamese in rural Kratie, while United Nations human rights envoy Thomas Hammarberg has voiced disgust at the tactics.

'If you want to be seen as someone who protects human rights, you can't violate that principle,' he said.

Should opposition figures win, diplomats fear illegal immigration crackdowns and border disputes could imperil relations with the giant neighbour to the east.

Mr Sam Rainsy is sticking too to pledges of anti-corruption drives and open government. He remains in the race despite constantly expressing fears that the CPP is interfering with fair elections.

Human rights workers echo his sentiments, saying international efforts to independently monitor the polls under the UN are unlikely to be critical whatever happens.

Human rights activists are already investigating 22 killings with alleged political overtones.

'Given the history of violence in Cambodia, the outside world is wrong to be obsessed by the 'body count' in deciding whether the elections are free and fair,' a human rights worker warned.

'It's the quiet but pervasive intimidation by the CPP that will swing this election. As soon as you leave a main road in Cambodia, you are in CPP territory.

'Their old communist-styled cell network is still vast.

'In the sticks, it is unclear if some people even know they are free to vote in secret for whoever they wish.' With no reliable polls it is difficult to gauge possible outcomes. With 39 parties contesting 122 National Assembly seats, a coalition is likely - especially as a party needs 81 seats to rule outright.

Many insiders fear tension and violence if the result is less than clear, given the assumption that Mr Hun Sen will never give up and the deep-seated bitterness between all main players.

On Friday, Mr Hun Sen said the 'door was always open' for a deal with Mr Sam Rainsy - a man who has called him a murderer, drug trafficker and log-smuggler, but who has never ruled out working with him.

Both Asian and Western diplomats believe any coalition with Mr Sam Rainsy would be difficult given a style seen as autocratic and elitist.

Trouble could also start brewing if Mr Hun Sen does not secure votes to be the main player in any negotiation.

Observers fear his CPP may try to push him out to strike a deal - an event which could give new powers to members of his inner circle such as his police chief Hok Lundy - a man whose opponents claim is not above using murder and violence as a political tool.

In the end it will have to be the king who swears in the new leader.

Asian diplomats claim he has told them he wants his son out of politics and would be prepared to work with Mr Hun Sen and delay overseas medical check-ups to ensure a smooth transition.

Whatever the king's role, Cambodia's poor and illiterate will have their say this week.