The youth, Saif Jafari, is said to be the spokesman of Mulayam Singh Youth Brigade's Bijnore unit.
As the press meet started, Jafari threw an egg towards Vishwas and waived a paper stating that Vishwas had hurt religious sentiments of both majority and minority communities and it "will not be tolerated".
Jafari, a native of Bijnore, was later nabbed by the AAP workers and handed over to the police.
Vishwas, who is tipped to contest from Amethi, a seat represented by Congress leader Rahul Gandhi, termed it as a "frustration" on the part of the opposition parties.
If these political parties think that by throwing eggs, inks, organising attacks they can win elections they should better look towards Delhi, he said.