By Joseph Winter
BBC News website, Kinshasa
Election workers in Democratic Republic of Congo have worked to set up possibly the most complex and challenging election the world has ever seen.
Election materials have to get to 50,000 polling stations
Helicopters, canoes, motorbikes and porters have been used to transport election material to almost 50,000 polling stations across a country two-thirds the size of western Europe, with just 300 miles of paved roads.
Behind the barbed wire which surrounds the Independent Electoral Commission (CEI) headquarters in the capital, Kinshasa, officials were scurrying around with just hours before the polls opened at 0600 (0500 GMT) on Sunday.
Outside, a tank from the United Nations peacekeeping force, Monuc, stood guard in case of trouble.
And tempers were rising at a second CEI office in the city, besieged by maybe 100 voters who have lost their voting cards.
They were worried they might not be able to play their part in these historic elections - the first multi-party polls for more than 40 years.
Issa Simba said he had left his card in a taxi a month ago, since when he had been continuously trying to get a replacement.
Elize Mbombo said she had been promised she would be able to pick up a replacement card on Friday but they were not ready.
"I would feel terrible if I could not vote - I want to know that our leader owes me something," she told the BBC News website.
Inside, representatives of some of the 250 different registered parties were busily filling out accreditation cards for their election agents.
They said the CEI should have done this ages ago, but they were diligently doing it themselves and thought they would be ready in time.
CEI spokesman Dieudonne Mirimo said organising the elections had been an extremely tough task but he was confident that everything was already in place and everything would go smoothly.
DR CONGO POLLS
32 presidential candidates
9,709 parliamentary candidates
50,000 polling stations
260,000 electoral staff
Monuc has worked closely with the CEI to prepare for the polls and ensure stability after the end of a five-year war, which left between three and four million people dead.
"These are the largest and most complex elections the UN has ever been involved in," said Monuc spokesman Kemal Saiki.
The elections are supposed to take DR Congo into a new era, following the official end of the 1997-2003 conflict.
Several leaders of the various armed groups were brought into a power-sharing government but are now running against each other in the elections.
They have retained they own personal security forces and in the last couple of days, as the election campaign came to a climax, they have clashed in the capital, Kinshasa, leading to at least three deaths.
However, Mr Saiki said that considering the country's troubled history, the election campaign had seen a remarkably low level of political violence.
As if a history of conflict, no electoral tradition and hardly any infrastructure were not enough of a problem, there are 9,709 parliamentary candidates and 32 for the presidential race.
With about half the population unable to read or write, each candidate has their name, number, photo, party and party symbol on the ballot paper.
Voters will choose from among 33 presidential candidates
In Kinshasa, the voting slip is the size of a local newspaper - eight tabloid-sized pages.
Campaigning has often come down to reminding voters of a candidate's place on the ballot paper - "Vote for number 247, page 4."
As a result of all the logistical challenges, these elections more than any other, are unlikely to be perfect.
Mr Mirimo said that a lorry containing the election material for about 30 polling stations had just been burnt in DR Congo's diamond capital, Mbuji-Mayi, home to an opposition leader who has called on his supporters to boycott the vote.
He said they would try and send spare election materials but if they were not available, voters registered at the affected polling stations would not be able to cast their ballots.
The UN's largest peacekeeping force is on hand
Many Congolese, especially those opposed to President Joseph Kabila, fear that the elections which are supposed to put the "Democratic" into Democratic Republic of Congo will not be free and fair.
He enjoys the advantages of incumbency, so important in Africa with a tradition of deep respect to leaders, and his campaign has certainly been the best financed.
The opposition says Mr Kabila is the favoured candidate of the west, which wants to exploit DR Congo's vast mineral reserves.
For them, the UN involvement is not a guarantee of impartiality but rather a smokescreen to help install their puppet.
This is vigorously denied by election officials, who point out that the agents of the various candidates, as well as five ordinary voters will witness the counting of the votes, which will start straight after voting ends at 1700 local time (1600 GMT in western DR Congo, 1500 GMT in the east).
The results from each polling station will then be posted outside and transmitted to regional and national centres for collation and publication.
By the same token that ordinary Congolese are not used to voting, Congolese politicians are not used to losing, leading to fears of renewed conflict, with the losers likely to blame their defeat on electoral fraud.
Nevertheless, Mr Saiki says he is cautiously optimistic, pointing out that the former military leaders have already fought a war, which did not work out.
Former rebel leader turned Vice-President Azarias Ruberwa told the BBC News website he would not start a new rebellion if he believed he had been cheated of victory but he would use "democratic means to prevent a false leader from governing".
Millions of Congolese are excited at the prospect of taking part in such historic polls - even in Kinshasa, where election fever had been slow to catch on. But many are also afraid of what may happen after the results are announced.