Biman Bose also criticized Somnath Chatterjee for dragging late CPM leader Jyoti Basu's name into the controversy.
"I feel that these are rubbish. If somebody wants to malign the party, that is in bad taste and is sad," said Bose.
"Jyotibabu is no more, one should not put words into his mouth. Communist etiquette does not allow such behaviour. Anybody can present a dead man's comments anyway he wants to. Whether he has really said that cannot be confirmed or denied", he added.
Chatterjee, former Lok Sabha Speaker, has made several comments against Karat and the present party leadership in his book 'Keeping the Faith: Memoirs of a Parliamentarian'.
Chatterjee has described that the disastrous policies and misguided actions of the current leadership of CPM had resulted in the major debacle in the 2009 general elections.
He alleged that Karat's ignorance and intolerance was demonstrated when he was summarily shown the door without a showcause notice.
Chatterjee was expelled from the CPI-M for refusing to resign from the post of Lok Sabha Speaker before the confidence vote in Parliament in 2008.