The Senate President, Abubakar Bukola Saraki has said his chances of leaving the ruling All Progressives Congress (APC) are “very, very high”.
Reuters reports Saraki saying this shortly after 14 APC senators defected to the Peoples Democratic Party (PDP).
The Senate president has been having a running battle with the federal government.
In June, the police invited him for questioning over the robbery in Offa, Kwara state.
The suspects arrested in connection with the incident reportedly confessed he bought arms for them.
After a public outcry, the police asked the Senate president not to appear but explain in writing, which he did.
But on Monday, Ibrahim Idris, inspector-general of police (IGP), summoned Saraki over the heist, saying there was need for the Senate president to make further statements on the incident.
Saraki had responded that the invitation was politically-motivated.
He said it was a plot to distract those willing to leave the ruling party from not doing so.
A siege was laid to the residence of Saraki in Abuja on Tuesday but the police denied involvement, accusing the Senate president of stage-managing it to whip up sentiment.