He alleged that the National Accountability Bureau (NAB) committed vote-rigging by sending notices to PPP workers and their families.
PS-11 Larkana-II by-election
The ECP is bound to hold transparent election under the law of the land, the spokesman said.
Firdous Ashiq Awan, in her message on a social media website, said, "The yesterday's by-poll has proved that Larkana is not the Bhuttos' stronghold anymore."
A tight electoral contest is expected between two candidates including Pakistan People's Party's Jameel Ahmed Soomro and Moazzam Ali Khan Abbasi of the Grand Democratic Alliance (GDA).