CPI(M) today rejected BJP's offer of debate in Parliament on Lalit Modi controversy and stuck to its demand for a fair investigation and the resignation of External Affairs Minister Sushma Swaraj and Rajasthan Chief Minister Vasundhara Raje over the issue. <br/><br/>Briefing reporters in New Delhi, party General Secretary Sitaram Yechury said debate in Parliament is no substitute for investigation and the onus is on the government to break the logjam. He also reminded BJP of its stand during the 2G spectrum allocation scam where the Winter Session in 2010 was a complete wash-out over the demand of resignation of the then Telecom Minister A Raja.<br/> <br/>The CPI(M) leader also demanded the resignation of Madhya Pradesh Chief Minister Shivraj Singh Chouhan over the Vyapam scam.