|Idriss Deby Itno is seeking his fourth term in a vote which the main opposition leaders are boycotting [AFP]
Voters went to the polls in Chad, with Idriss Deby Itno, the country's sitting president, virtually assured of re-election after his three main opposition rivals announced a boycott.
Saleh Kebzabo, Wadal Abdelkader Kamougue and Ngarlejy Yorongar have withdrawn from what they have described as an "election circus" and have urged citizens to boycott Monday's vote.
Having demanded reforms that include the issuing of new voters' cards, they claim that unfair conditions caused Deby's Patriotic Movement of Salvation (known by its French acronym MPS) to crush them in a February parliamentary poll and are predicting the new poll will be a "historic fraud".
Witnesses said many voting stations opened late in the capital because of the late arrival of voting materials and staff.
The ballot was underway in the district of Djambalpar where residents said they were pleased to be coming out to vote.
"I'm very happy to come to vote today to fulfil my civic duty," Youssouf Zeni, 58-year-old civil servant, said.
At an election meeting on the last day of campaigning on Saturday, in a jam-packed N'Djamena stadium that can seat 20,000 people, Deby invited Chadians to "abandon ideas that divide us".
His three main opponents, in turn, addressed a rally attended by more than 1,000 people earlier in the day, urging voters to boycott the vote.
Kebzabo is the president of the National Union for Democracy and Renewal, the opposition party with the most national assembly seats, nine, followed by Kamougue's Union for Renewal and Democracy with seven seats, and Yorongar's Federation Action for the Republic, with four.
Deby's MPS party won an absolute majority with 113 of the 188 seats in parliament against a fragmented and underfunded opposition of more than 100 parties in February's parliamentary elections, the first contested by the opposition since 2002.
In Monday's vote, he will face two candidates from smaller opposition parties: Albert Pahimi Padacke and Nadji Madou.
Deby has been in power since 1990 after unseating dictator Hissene Habre in a coup.
Seeking a fourth five-year mandate, he has said he is certain of re-election and that the poll will be "credible". The real reason for his former challengers' boycott was that "they realise they will be beaten," the president told a press conference on Friday.
With other parts of the Muslim world rocked by months of protests against long-serving rulers, Deby said he was only in power because his country wanted him.
"If the people had not asked me to be a candidate and to continue to serve Chad, I would never have done it," he said, adding he would focus his next term on helping the rural poor.
An observer told the AFP news agency that the only test of Deby's support will be in the voter participation rate - which the president himself has predicted will exceed that of February's poll.
Yorongar, though, has forecast a high abstention rate.
"The boycott will be heeded, but the system of fraud will ensure that Deby gets 90 or 95 per cent," he said on Saturday.
Sandwiched between volatile neighbours Niger and Sudan, Chad is one of Africa's poorest countries, despite abundant resources of uranium and gold.
It became an oil producer in 2003 following the completion of a $4bn pipeline linking its oil fields to depots on the Atlantic coast.
About 4.8 million of Chad's 11.1 million citizens are eligible to cast ballots, along with around 233,000 expatriates.