In a statement issued by his media aide, Mr Paul Ibe, in Abuja, Abubakar said that the purpose of the siege was to force a change in the leadership of the Senate.
The security personnel, who barricade entrance to the assembly complex as early as 7 a.m., barred lawmakers of Peoples Democratic Party (PDP) and those who recently defected from All Progressives Congress (APC), from entering the premises.
He condemned “completely, this atrocity and call on all those involved to put Nigeria first and abandon this madness.
“The Constitution of the Federal Republic of Nigeria, as amended, guarantees both the independence of the legislature and Separation of Powers.
“Nigeria is a democracy not a military dictatorship and we, the people will never return to tyranny.”
The former vice president also urged President Muhammadu Buhari and Acting President Yemi Osinbajo to uphold the Constitution and law and order, which they swore to on May 29, 2015.
“We warned that if what occurred in Benue last week was not checked on time, it would escalate to the federal level. Today we are seeing that warning in play.
“The Acting President, being himself, a professor of law, ought to know that setting such a precedent is an invitation to anarchy’’.
He said that there were better uses of the security forces at this time than to lay siege to the country’s citadel of democracy.
“Our people are languishing in the midst of unprecedented insecurity and nationwide killings.
“To, therefore, deploy our security forces in this present manner while Nigerians face these challenges is an abdication of responsibility, to say the least.”