"Mamata Banerjee should now make herself prepared for CBI interrogation," Bose told reporters at Malda Town station.
Bose, who demanded Mitra be sacked from the state cabinet with immediate effect, mocked at Banerjee's complaint of "political vendetta" behind the arrest, which the Trinamool Congress supremo had also termed as unconstitutional.
"The questions do not arise. The moot question now centres around existence of the government," the CPI(M) Politburo member said en-route to Raiganj for a party meet.
"Mamata Banerjee should be quizzed immediately in the Saradha scam," Mishra, also a CPI(M) Politburo member told reporters in Kolkata.