"I am not aware as to who has constituted this National Disciplinary Committee and when and how this was done," said Mr Bhushan. He and Yogendra Yadav were served notice for "anti-party activities" last week after they launched a "Swaraj Abhiyan (self-rule campaign)," seen by many as a prelude to a breakaway party.
He targeted two members, Pankaj Gupta and Ashish Khetan, saying, "You had complained against me and now want to become judges of your cause."
"You also know that there have been serious charges against you yourself," said Mr Bhushan, reminding them that he headed the panel until recently. He alleged that Mr Gupta had accepted 'donations' of Rs. 2 crore from shell companies without taking the approval of the Political Affairs Committee.
He said Ashish Khetan, a former journalist, had been accused of "writing a planted story for Tehelka in defence of the Essar Company," which was charge sheeted by the CBI in the 2G spectrum case.
In response, AAP's Ashutosh said Mr Bhushan "is making a laughing stock of himself."
"Either Prashant Bhushan proves these allegations or else he should apologise. Enough is enough," Ashutosh said, adding that "Khetan is a journalist with an impeccable image."
Mr Yadav and Mr Bhushan have alleged that they are being hounded and victimized for taking on Arvind Kejriwal and objecting to what they call his dictatorial ways.