His campaign organisation said President Buhari has made Nigeria one of the poorest in the world.
President Buhari had remarked on Tuesday, September 11, 2018, that politicians that have dumped his All Progressives' Congress (APC) for opposition parties are the weakest "whose sense of expectation do not align with our vision". Atiku left the party to return to the People's Democratic Party (PDP) in 2017.
In July and August, the APC was hit with a wave of defections that saw three state governors and dozens of lawmakers, including Senate President, Bukola Saraki, dump the party with many joining the ranks of the PDP.
In response to Buhari's remarks, the Atiku Campaign Organisation spokesperson, Segun Sowunmi, said the defection of top officials from the APC to the PDP signals Buhari's inability to keep Nigerians united.
Sowunmi said Atiku will take the presidency from Buhari to clean up his mess which has resulted in job loss, poor economy and ranking of the country as one of the poorest.
He said, "Never in the history of Nigeria has a more incompetent person served in the chambers of the exalted office of the President. No President of Nigeria, politics apart, will speak in such manner. The fact is that freedom of association is guaranteed by all the United Nations' conventions and the constitution of our country.
"That Buhari has not been able to provide leadership and keep high-network individuals in the APC is to his own weakness and a question of his lack of capacity to keep Nigerians together. We are in the campaign and we are on the ballot. Atiku is attempting to become the President to clean the mess that Buhari caused in our country.
"Buhari has made many Nigerians lose their jobs and our country has become one of the poorest countries in the world. He has divided the country and people cannot move freely. He has made a mess of the economy.
"Therefore, we take his comment as not possibly referring to us. He should speak to issues, development, job creation, restructuring and so on. Obviously, these things he cannot do."
While he's one of the favourites to win the presidential ticket of the People's Democratic Party (PDP), Atiku will have to defeat a lot of influential politicians who have also set their eyes on the prize.
He faces competition in Senate President, Bukola Saraki, Sokoto State governor, Aminu Tambuwal, Gombe State governor, Ibrahim Dankwambo, and former governors, Sule Lamido, Attahiru Bafarawa, Jonah Jang, Ahmed Makarfi, as well as Rabiu Kwankwaso.
Others are former Senate President, David Mark, former Senator, Baba Datti Ahmed, and former Minister Special Duties Duties and Inter-governmental Affairs, Tanimu Turaki.