The battle for Presidency of 9th Senate opened on Tuesday as senators-elect commenced polling to choose their number one senator.
The contest is between Ahmed Lawan and Ali Ndume, both elected on the platform of the All Progressives Congress (APC).
In the chambers, 107 senators-elect out of 109, were accredited for the exercise being conducted by the Clerk of the National Assembly, Mr Mohammed Omolori.
Two senatorial districts in Imo currently do not have representations in the Senate following issues that arose from the general elections.
The News Agency of Nigeria reports that a mild drama ensued before polling commenced as the senators were divided over voting pattern to be adopted.
Some members opted for the 2011 Senate Rule which stipulates open ballot, while some, mostly of the Peoples Democratic Party (PDP), insisted on the 2015 Rule, which stipulates secret ballot.
On argument of a court order directing the use of 2015 Rule, the clerk denied receiving such order, thereby dousing tension that had arisen.