The youths, under the aegis of the Almagamated PDP Youth Leaders Nationwide, stated this at a press briefing in Abuja on Wednesday.
They said it was an embarrassment for Sheriff to have walked out on Jonathan, who they described as the leader of the party.
Chairman of the group, Segun Aderemi, has now given Sheriff a 7-day ultimatum to tender an unreserved apology to Jonathan and other party leaders.
“We witnessed what happened that day when he walked out on the former President. Would Sheriff be happy if any member of the party embarrass him the way he embarrassed Jonathan that day?
“He has to tender an unreserved apology to the former President, the BoT and other leaders of the party.