Nigeria poll challenge dismissed
Nigeria's Supreme Court has rejected the final challenge to last year's election of President Umaru Yar'Adua.
Opposition leaders had asked the court to annul the election, saying there had had been violence and fraud.
Local and foreign poll observers condemned the elections in April last year as flawed.
But the Supreme Court has upheld the findings of lower courts that lawyers had not provided strong enough evidence to overturn the official result.
"In sum, this appeal failed and is dismissed. Accordingly, Umaru Yar'Adua and Dr Goodluck Jonathan are the president and vice-president of the Federal Republic of Nigeria," said Supreme Court justice Niki Tobi.
The BBC's Alex Last in the capital, Abuja, says legal wrangling over the election has undermined President Yar'Adua's first 18 months in office.
Nigeria faces a growing economic crisis because of the falling price of oil, the West African country's biggest source of income.
Lawyers for the former Vice-President Atiku Abubakar said the presidential election result should be overturned because ballot papers were not properly printed and were delivered with only hours to go before voting was due to start.
Anywhere more than five hours drive away from Abuja did not get ballot papers until the evening of the election day, some not until the day after.
But the result was declared in Abuja less than 48 hours later, while some states were still voting.
Opposition MPs said the results were announced before all the votes had been counted.
The run-up to the elections had seen violence in Mr Yar'Adua's home state of Katsina, and in the northern city of Kano.
Opposition supporters burned down an office of the Independent National Election Commission in Katsina.
In Kano, a group of armed men took over a police station, killing more than 100 officers and bystanders before they were killed by the army.
Their motivations for the attack are still not clear, although many agree that it may have been an attempt to destabilise Kano State, an opposition stronghold.
The election tribunal in March had rejected the evidence collected by the opposition's lawyers.
Much of the evidence was based on newspaper reports of the election.
Some of the eyewitness accounts accusing the government of rigging the election filed by presidential candidate Muhammadu Buhari's legal team were shown to have come from friends and family of the lead lawyer, Mike Ahamba.
Government supporters say this result will free President Yar'Adua to deal with the challenges facing the country.
Nigerians live with a woeful power supply, there is violence in the southern oil-producing region, and the country is facing a budget deficit caused by the tumbling price of oil.
But critics say that President Yar'Adua, who has been given the nickname "Baba-go-slow", is incapable of dealing with these problems.
They point to the glacial pace the government deals with basic functions like naming ministers, and persistent fears about the president's state of health.