Former vice president Atiku Abubakar has defected to Nigeria's main opposition party, adding a heavyweight name to a group that poses an increasing threat to the ruling People's Democratic Party (PDP) in elections next year.
Abubakar, a founding member of PDP and vice president between 1999-2007, joins five state governors and dozens of lawmakers who have recently signed up with the All Progressive Congress (APC), which has used its increasing weight to threaten to block this year's budget in parliament.
Africa's second largest economy and top oil exporter is growing as an investment destination but political upheaval is a concern for investors, especially as elections often see a spike in government spending and a fall in oil savings.
"The PDP continues to be beset with many crises, mostly leadership-induced crises,'' Abubakar said in a statement.
"It has lost touch with Nigerians and efforts made by many well-meaning members and stakeholders to bring it back to the vision of the founders have been rebuffed.''
Abubakar has long been a critic of President Goodluck Jonathan. Most analysts had expected Abubakar to either run against him for the PDP leadership or defect to an opposition party before the February 2015 presidential election Jonathan is favorite to win if he chooses to run.
By joining newly formed APC, he adds weight to the group but also may add to the risk of clashes among a number of high-profile personalities such as former military ruler Muhammadu Buhari and Lagos Godfather Bola Tinubu.