Posted by By Elizabeth Blunt, BBC News on
A leading official in Nigeria's ruling party has called on Vice President Atiku Abubakar to remain loyal to President Olusegun Obasanjo or resign.
There is now open tension between them over the issue of the succession.
Mr Atiku is generally assumed to want to succeed President Obasanjo after he completes his second term.
But there have been suggestions the constitution might be changed to allow the president a third term in office.
But according to Nigeria's constitution as it now stands, President Obasanjo can only serve two terms so the ruling party will have to pick a new presidential candidate for 2007, and Vice-President Atiku has never hidden the fact that he would be happy to be that candidate.
But the vice-president has clearly become increasingly irritated by some of the people who surround the president, singing his praises and urging him to try to get a third term in office.
In a long newspaper interview last week he complained about the president's failure to speak out against this, saying that it was what he called 'doublespeak' to allow this campaign to go on.
President Obasanjo hit back in a radio press conference, accusing his deputy of mis-presentation, misrepresentation and misinformation, and talked about what he called 'proven cases of disloyalty' on Atiku's part.
For the vice president, this public spat has coincided with other worries, with his house in the United States being raided as part of an FBI investigation into the business affairs of a US Congressman, William Jefferson.
No allegations of wrongdoing have been made against Atiku Abubakar, but it's a bad moment for him to have his name linked - however indirectly - to any kind of criminal investigation.