Congress spokesperson Priyanka Chaturvedi also accused Irani of misusing her influence and power as a Union minister.
"Union Minister Smriti Irani, who had been rubbishing Opposition's claim that she is not a graduate, yesterday accepted that she enrolled for an undergraduate course in Delhi University but did not complete it," Chaturvedi said.
She should step down and also be disqualified from contesting the polls, Chaturvedi said.
"We have no issue with the fact that Smriti Irani is not a graduate. The issue here is that she has lied repeatedly on oath and to the courts. People of India will see through these lies and give a befitting political reply to a 'serial liar'!"
It is clear that she has not only "falsified records" of her degrees but has submitted contradictory affidavits to the EC for which she is guilty of offence under Section 125A read with Section 33 of the Representation of Peoples Act, Chaturvedi said.
Parrying questions from reporters over the affidavit row, Irani said the more they (Congress) attack, the harder she will work against them in Amethi.
“In the last 5 years, they have attacked me in every which way possible. I only have one message for them, the more you will insult me, the more you will attack me, the harder I will work against Congress in Amethi,” she said.
Irani on Thursday submitted to the Election Commission that she did not complete her graduation from Delhi University.
In her affidavit filed during her nomination, Irani, who is contesting against Congress chief Rahul Gandhi, said she passed secondary school examination in 1991 and senior secondary school examination in 1993.
Irani has said she did not complete her Bachelor of Commerce (Part-I) - a three-year degree course - from Delhi University's School of Open Learning in 1994.
In her affidavit for 2014 polls, she had reportedly said she graduated from the university in 1994, triggering a row over the veracity of her claim, with opposition parties alleging she was not a graduate.
(With additional information from PTI)