Merino, Congress chairman who had assumed the post of interim president after the sudden impeachment and ouster of former president Martin Vizcarra over bribery charges on Nov. 9, announced his resignation on Sunday.
Ever since Merino's appointment, Vizcarra's supporters launched mass rallies on a daily basis to protest the ex-president's ouster. The growing public anger eventually resulted in Merino announcing that he was stepping down on Sunday.
Merino's resignation followed an ultimatum from Congress for him to resign or face censure over the death of two protesters and the injury of about 100 others in Sunday's rallies which reportedly came as a result of police firing tear gas and rubber bullets.
Congress failed to name Merino's successor on Sunday.