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.
"Such an incident occurred during a press conference before Delhi elections, during which black ink was thrown towards Arvind Kejwariwal," he said, adding that his party later went on to form the government.
If these political parties think that by throwing eggs, inks, organising attacks they can win elections they should better look towards Delhi, he said.