The audio clip suggests that Surendran had indeed offered bribe money to JRP leader C K Janu ahead of the 2021 Kerala Legislative Assembly election.
Earlier, CPM district secretary R Nazar had revealed that an explanation has been sought from Prathibha over her criticism of the party leadership on social media.
The Metroman said that he is no longer disappointed with the outcome of the elections, and had learned many things.
Representatives of four district units led by Sheikh P Harris and V Surendran Pillai are set to meet party supremo Sharad Yadav to demand the resignation of the state president.
The CPM state secretariat took the action on the former minister after an internal enquiry found that he had cold-shouldered the party's chances in the assembly constituency.
The party suspends NC Mohanan and CK Manishankar for failure in key constituencies during the assembly polls.
The case was registered after it surfaced that money was paid to the BSP candidate K Sundara to withdraw his nomination at the Manjeswaram assembly constituency in the April 6 assembly polls.
Action was initiated after the CPM reviewed the defeats in Tripunithura, Thrikkakara, Piravom and Perumbavoor constituencies.
Further, the CPM State Committee-approved election review report also found that the party's failure resulted in Kerala Congress (M) chief Jose K Mani's debacle in Pala segment.
The ruling CPM's assembly election review report contains specific references indicting the veteran leader in connection with the campaign.