The BBC's Caroline Gluck reports from Phnom Penh

The elections are the first to be organised by the Cambodians themselves since a UN-organised vote five years ago. A total of 39 parties are taking part.

Former first Prime Minister Prince Ranariddh was deposed in a coup last year

The polls come little more than a year after the former first Prime Minister, Prince Norodom Ranariddh, was ousted from power in a coup by the leader of the Cambodian People's Party (CPP), Hun Sen.

Prince Ranariddh's party won the largest share of votes in the last election.

Intimidation fears

Opposition politician Sam Rainsy has said political intimidation and restrictions on access to electronic media make the campaign process unfair for opposition parties. He has said he will withdraw from the poll if improvements are not made.

Sam Rainsy says there is a campaign of intimidation against opposition parties

Human rights groups and international donors have also voiced concern. They say they are worried by Cambodia's current political climate, and will be closely monitoring events over the next few weeks before polling day, hoping for positive signs of change.

Total control

Hun Sen has been in almost total control of Cambodia since the July 1997 coup. His party says its main priorities are the battle against poverty, and against the remnants of the Khmer Rouge guerrillas, who are still active in some areas of the north.

Hun Sen

He has said he will bring the surviving leaders of the outlawed guerilla group to trial.

Prince Ranariddh, who fled the country after fighting between two wings of the former coalition government, says he believes the central issue is democracy.