Abubakar confirmed this in a statement he personally signed on Friday.
He also gave reasons for quitting the party.
However, he did not state which party he intends to join, but said he is pondering on his political future.
The statement, titled: “Statement of resignation of His Excellency Atiku Abubakar (Waziri Adamawa) Vice President of Nigeria, 1999-2007 from the All Progressives Congress,” reads in full…
“On the 19th of December, 2013, I received members of the All Progressives Congress at my house in Abuja. They had come to appeal to me to join their party after my party, the Peoples Democratic Party, had become factionalized as a result of the special convention of August 31, 2013.
“The fractionalization of the Peoples Democratic Party on August 31, 2013 had left me in a situation where I was, with several other loyal party members, in limbo, not knowing which of the parallel executives of the party was the legitimate leadership.
“It was under this cloud that members of the APC made the appeal to me to join their party, with the promise that the injustices and failure to abide by its own constitution which had dogged the then PDP, would not be replicated in the APC and with the assurance that the vision other founding fathers and I had for the PDP could be actualized through the All Progressives Congress.
“It was on the basis of this invitation and the assurances made to me that I, being party-less at that time, due to the fractionalization of my party, accepted on February 2, 2014, the hand of fellowship given to me by the All Progressives Congress.
“On that day, I said “it is the struggle for democracy and constitutionalism and service to my country and my people that are driving my choice and my decision” to accept the invitation to join the All Progressives Congress.
“Like you, I said that because I believed that we had finally seen the beginnings of the rebirth of the new Nigeria of our dreams which would work for all of us, old and young.
“However, events of the intervening years have shown that like any other human and like many other Nigerians, I was fallible.
“While other parties have purged themselves of the arbitrariness and unconstitutionality that led to fractionalization, the All Progressives Congress has adopted those same practices and even gone beyond them to institute a regime of a draconian clampdown on all forms of democracy within the party and the government it produced.
“Only last year, a governor produced by the party wrote a secret memorandum to the president which ended up being leaked. In that memo, he admitted that the All Progressives Congress had ‘not only failed to manage expectations of a populace that expected overnight ‘change’ but has failed to deliver even mundane matters of governance’.
“Of the party itself, that same governor said ‘Mr. President, Sir Your relationship with the national leadership of the party, both the formal (NWC) and informal (Asiwaju Bola Tinubu, Atiku Abubakar, Rabiu Musa Kwankwaso), and former Governors of ANPP, PDP (that joined us) and ACN, is perceived by most observers to be at best frosty. Many of them are aggrieved due to what they consider total absence of consultations with them on your part and those you have assigned such duties.
“Since that memorandum was written up until today, nothing has been done to reverse the treatment meted out to those of us invited to join the All Progressives Congress on the strength of a promise that has proven to be false. If anything, those behaviours have actually worsened.
“But more importantly, the party we put in place has failed and continues to fail our people, especially our young people. How can we have a federal cabinet without even one single youth.
“A party that does not take the youth into account is a dying party. The future belongs to young people.
“I admit that I and others who accepted the invitation to join the APC were eager to make positive changes for our country that we fell for a mirage. Can you blame us for wanting to put a speedy end to the sufferings of the masses of our people?
“Be that as it may be, after due consultation with my God, my family, my supporters and the Nigerian people whom I meet in all walks of life, I, Atiku Abubakar, Waziri Adamawa, hereby tender my resignation from the All Progressives Congress while I take time to ponder my future.
“May God bless you and may God bless Nigeria.”