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ABUJA Jan 24 Nigeria's electoral commission declared on Friday that presidential and parliamentary elections would take place on Feb. 14 next year.
The elections are expected to be the most closely fought since the end of military rule in 1999.
President Goodluck Jonathan's supporters are embroiled in a bitter dispute with other members of the ruling party over whether or not he should seek another term in office.
The election of powerful state governors will also take place on Feb. 28 next year, the statement from the Independent Electoral Commission (INEC) said, except in the states of Ekiti and Osun, which would take place on June 31 and Aug. 9, respectively.
Politics has become increasingly heated in Africa's top oil exporter since four opposition parties merged last February. Five state governors and dozens of lawmakers defected from the ruling People's Democratic Party (PDP) late last year.
The opposition coalition is stronger than any previous one, although analysts say it represents diverse interests that could easily fall apart as polling day approaches.
Political wrangling has delayed crucial legislation, including the 2014 fiscal budget, and looks likely to ignite violence similar to that which has marred previous elections. (Reporting by Camillus Eboh; Writing by Tim Cocks; Editing by Sonya Hepinstall)