President Deby's supporters are hoping for a third term
Chad goes to the polls on Wednesday to elect a new president, despite an opposition boycott and calls for voting to be postponed.
Five candidates are standing, among them President Idriss Deby, who is seeking a third term in office.
What's at stake?
Chad has been one of Africa's most unstable countries since declaring independence in 1960, and that has been brought into sharp focus in the weeks leading up to polling day.
In mid-April, rebels seeking to oust Mr Deby battled government forces on the outskirts of the capital, Ndjamena.
That attempted coup was defeated, and in the wake of the fighting, Chad severed diplomatic ties with its neighbour Sudan, whom it accused of backing the rebels.
But Mr Deby continues to face defections to rebel ranks by senior army officers.
The government is also struggling with the task of handling tens of thousands of refugees who have come across the Sudanese border from Darfur.
As in previous elections, security is a key campaign issue.
What about the economy?
Economic development in Africa's fifth-largest country has been severely hampered by poor infrastructure and internal conflict.
Prospects improved in 2003 when Chad started producing oil and shipping it to terminals on the African coast.
However, the flow of benefits from this wealth was interrupted in January when the World Bank suspended loans and blocked an account in which oil revenues are deposited.
These measures were lifted at the end of April, after Chad gave assurances that more of the proceeds from oil sales would be used to aid the country's poor.
But Chad remains one of Africa's most impoverished nations.
Who are the candidates?
A career soldier now in his mid-50s, Mr Deby belongs to the Zaghawa, a small ethnic group from the east and northeast of Chad.
He originally came to power in 1990, and ruled provisionally until 1996.
He has since won presidential polls in 1996 and 2001, although both victories were marred by claims of electoral fraud.
Despite initially saying that he would not stand again, Mr Deby organised a constitutional referendum in 2005 which removed the two-term limit for the presidency, paving the way for him to seek a third term.
In the current campaign, he has sought to portray himself as Chad's best chance of securing peace and stability.
All four remaining candidates are known to be political allies of the president.
They include one of Mr Deby's former prime ministers as well as two serving members of the cabinet.
Why is the opposition not taking part?
The mainstream opposition parties argue that the electoral process has been manipulated to deliver a further term in office for Mr Deby.
They have accused the government of tampering with the electoral roll, abusing election laws and reshuffling the Independent National Electoral Commission (CENI) to favour the president.
Mr Deby denies these claims, and says there is no reason why the election should not go ahead as planned.
In the meantime, the boycott has led to calls at home and abroad, including from the African Union and a senior US diplomat, for polling day to be postponed.
Two of the main rebel groups are reported to have joined forces with the aim of disrupting the remainder of the campaign.
This is the first time since the introduction of multi-party politics in Chad 15 years ago that the opposition has boycotted a presidential election.
Who will be voting?
No registration of voters has been carried out ahead of polling day, another reason the opposition decided to announce a boycott.
Instead, the authorities are expected to use a list of voters compiled ahead of the constitutional referendum in 2005. On that occasion, some 5.3 million Chadians registered to vote.
How will the election work?
Chad's president will be elected by universal suffrage. Any candidate who gains more than 50% of ballots in the first round of voting will be declared the winner.
Failing that, the two candidates gathering most support will go through to a second round, to be held within two weeks of the first. A simple majority will be enough to secure victory.
Polling is being overseen by CENI, although it is the responsibility of the Constitutional Council to declare the result.
What happened last time?
Seven candidates contested the last presidential elections, held on 20 May 2001.
Running as the incumbent, and backed by 27 political parties, Mr Deby swept to victory with 63% of the 2.4 million votes cast.
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