Saraki announced his defection to the People's Democratic Party on Tuesday after months of speculations amid a protracted battle with a power bloc in APC.
He defected to the APC from the then ruling party People's Democratic Party (PDP) in January 2014 along with ten other senators.
But he said belated peace efforts made by Osinbajo, Oshiomhole and governors would have made him to "to reconsider the situation" if such efforts were allowed to yield intended results.
"The emergence of a new national party executive a few weeks ago held out some hopes, however slender," Sarki said in a statement on Tuesday.
"The new party chairman has swung into action and did his best alongside some of the Governors of APC and His Excellency, the Vice President."
Oshiomole was elected the party's boss in June and he has set about appeasing some of the high-profile members of the party.
But his efforts have failed to preclude notable members from ditching the ruling party.
Last week, APC lost 15 senators and 37 members of House of Representatives to opposition parties.
It also lost Governor Samuel Ortom of Benue and twenty members of the Benue State House of Assembly. Kwara State governor also announced his defection to the PDP earlier today.
These defections may not have been if a powerful bloc in the party had allowed for a genuine dialogue to take place, Saraki said.
"As I have realized all along, there are some others in the party leadership hierarchy, who did not think dialogue was the way forward and therefore chose to play the fifth columnists," Saraki said.
"These individuals went to work and ensured that they scuttled the great efforts and the good intentions of these aforementioned leaders of the party."