"He has said from a stage here that a Mamata painting was sold for Rs 1.80 crore. You should prove it. I will resign from parliament, otherwise you should apologise to the country, Bengal and everybody," TMC national spokesperson and party's Rajya Sabha member Derek O'Brien told a press conference here.
TMC MP Derek O'Brien and WB minister Firhad Hakim threatend to quit
"I have said this before that he is the butcher of Gujarat. I am saying this today, I will again say this in future," the Trinamool leader said.
He said that cheques for the paintings were made out in the name of the party's mouthpiece 'Jago Bangla' which was a public document given to the Election Commission signed by party General Secretary Mukul Roy.
"Nothing is for Mamatadi, all is for Jago Bangla," Derek said.
Senior TMC leader and Minister for Urban Development Firhad Hakim also challenged Modi's claim saying, "I will resign as a minister if he can prove it. But Modi will also have to withdraw from the PM contest if he is proved wrong."
The TMC has already demanded a public apology from Modi for doubting the integrity of the party supremo over the sale of her paintings and also complained to the Election Commission besides threatening to file a defamation suit if the Gujarat chief minister did not apologise.
Earlier in the day, the state unit of the BJP threatened to file a counter-defamation case against the TMC.
The BJP also demanded that the TMC publish a white paper on the buyers of the paintings of the party supremo and on the Saradha chit fund scam.