Jaitley's comments came a day after Gandhi said that the Bharatiya Janata Party's (BJP) balloon will burst, like 2004.
"The Congressmen are living in denial," Arun Jaitley said in a blog post.
"What are the indications available with Rahul Gandhi that he has to call the groundswell for Modi a 'balloon that will burst'. Can he compare the size of Modi rallies with his own?" said the leader of opposition in the Rajya Sabha.
"Can he compare the enthusiasm of candidates wanting to fight on a BJP ticket and the reluctance of many to fight on a Congress ticket?
"He has still not seen the reality in the fact that the DMK, TRS (Telangana Rashtra Samiti), LJP (Lok Janshakti Party), TMC (Trinamool Congress), PMK and MDMK have all deserted the Congress. He believes that his allies are intact. The largest representation that the UPA got in 2004 and 2009 was from Tamil Nadu, and Andhra Pradesh. This time in these two states the Congress figure may nosedive," Jaitley said.