"A memorandum has been signed by all the opposition parties and it will be submitted to the Election Commission," Banerjee said.
The dharna began on Sunday night after a CBI team moved to arrest Kolkata police Commissioner Rajeev Kumar.
They were unceremoniously denied entry to Kolkata police chief's residence and then detained.
Kumar arrived earlier today to visit Mamata at the dharna site.
A 1989-batch IPS officer of West Bengal cadre, Kumar was heading a SIT on the Saradha and Rose Valley scams.
"The CBI wanted the top officer to hand over the seizure list made during his probe," sources said.
Reportedly, the top cop was to be questioned regarding missing documents and files but he is not responding to notices to appear before the agency.
With inputs from PTI.
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