Nigeria’s ruling People’s Democratic Party’s delegates have started arriving in Abuja from across the country to pick its presidential candidate for the April election amid tight security.

The major contenders are incumbent President Goodluck Jonathan and former vice president Atiku Abubakar who have large followers across the country.

The key issue in the primary may be the issue of rotational presidency which has been the major point of political debates this election period.

The third candidate is veteran woman politician Sarah Jibril. President Jonathan, who is from south, inherited power from former president Umaru Musa Yar’Adua, who was from north, after his death last year.

A power sharing agreement within the ruling party says power should rotate between the north and south every eight years and Abubakar is challenging Jonathan’s claim that his aspiration is a continuation of Yar’Aduas era.

“Over 5000 delegates are expected to decide who emerges as the presidential flag bearer of PDP for the April 2011 presidential election and accreditation is already going on at two locations at the International Conference Centre and the Women Centre,” Uche Secondus, the national organising secretary of the party, told PTI.

Sixty per cent of the delegates would come from the 19 northern states of the oil rich African country recently troubled by incidents of bombings and killings associated to ethnicity, militancy and religion.

Over 20,000 policemen made up of regular, anti-riot and anti-bomb units have been sent to the Eagle Square where the convention will be held today.

A bomb explosion rocked the same square on October 1 during the country’s 50th independence anniversary killing several persons and wounding others.

On Tuesday, the three presidential aspirants faced a panel of evaluators who cleared all of them giving them the go ahead to contest Friday’s primary.

Jonathan was the first to be interviewed by the panel and he came out to tell the media that the exercise was rigorous. Former vice president Abubakar said he was asked about his return to the party and some critical comments he made about the party when he contested in the last election on the platform of an opposition party, Action Congress (AC).

“I think the screening panel is a good panel,” Abubakar said.