Nigerian President Goodluck Jonathan, the strong favourite to win an April presidential election, has said he will stand for only one term, a move which may help to appease some of his northern opponents.

A win in April would entitle Jonathan, a southerner, to seek a second term in 2015 but he would be likely to face stiff opposition from some northerners in and outside the ruling People's Democratic Party.

Jonathan's candidacy in this year's polls interrupts a pact within the PDP that power should rotate between the largely Muslim north and mostly Christian south every two terms.

Jonathan assumed office after President Umara Yar'Adua, a northerner, died last year during his first term. Some northern politicians believe only a northerner should complete what would have been Yar'Adua's second term.

Jonathan confirmed his intentions in Addis Ababa on Monday, where he expressed his disappointment that Nigerians based abroad would be unable to vote in this year's elections.

I would have loved that Nigerians in the diaspora vote this year but to be frank with you that is going to be difficult now, Jonathan told Nigerians in Ethiopia's capital.

Nigerians in the diaspora will not vote but I will work towards it by 2015, even though I will not be running for election, he added.

The PDP has won every presidential race since the end of military rule in 1999 and after securing its nomination for the April 9 vote, Jonathan has emerged as the clear front-runner.

His main challenger in the election is likely to be former military ruler Muhammadu Buhari, a northerner whose reputation as a disciplinarian with a low tolerance for corruption make him popular among grass roots supporters in the north.

Buhari, who is running on the Congress for Progressive Change (CPC) platform, announced on Monday he had chosen popular Christian televangelist Tunde Bakare -- who preaches a radical opposition to corruption -- as his running mate.

Ibrahim Shekarau, governor of the northern state of Kano who is also running against Jonathan, picked John Odigie-Oyegun, former governor of the southern state of Edo, as his vice presidential candidate.

The U.S.-based International Republican Institute published a Nigerian opinion poll on Tuesday showing 74 percent of those it spoke to believed the elections would be more credible than those of 2007, which were marred by intimidation and fraud.

The poll of more than 3,000 people also showed high voter interest -- with 89 percent of those asked saying they would definitely or probably vote in the polls.

Lack of electricity, corruption and unemployment were the three main issues of voter concern.

Unemployment Elections Nigeria Ethiopia