Facing widespread opposition, Peru’s interim president resigned on Sunday, on his sixth day in office, pushing a country already facing an economic decline and a devastating pandemic into a constitutional crisis.

President Manuel Merino took office on Tuesday, after lawmakers shocked the nation by voting to impeach the popular former president, Martin Vizcarra, and then swear to Mr. Merino, who had been the president of Congress.

From his first moments in office, Mr. Merino faced opposition from Peruvians who took to the streets in protest and from prominent political and social leaders, many of whom said they did not recognize Mr. Merino as president.

On Sunday, after most of his cabinet members resigned and his last political allies abandoned him, the Congress that elected him called on him to step down. Mr Merino took a beware.

“I submit my irreversible resignation,” Mr. Merino said in a video address to the nation on Sunday. “I call for peace and unity for all Peruvians.”

Mr Merino said he will now focus on ensuring a smooth transition to a new leader to avoid a power vacuum. On Sunday, Congress announced that it would appoint a new president from among lawmakers later that day.

However, it was not clear whether the Peruvians would accept Mr. Merino’s successor as their leader and end the daily protests that are shaking the nation. The National Congress is not very popular in Peru – about half of its members are under investigation for corruption and other crimes – and many have blamed the political opportunism of its members for the current crisis.

Protests erupted on the streets of the capital, Lima, and then in other cities across the country after the majority of lawmakers voted on Monday to sack the then president, Mr. Vizcarra. Upon his impeachment, lawmakers cited unproven accusations of corruption and used an old constitutional provision that allowed Congress to declare the president morally incapable of leading the nation.

Mr. Vizcarra was due to step down after the presidential election in April, and had promised to face justice after leaving office. He garnered the support of the majority of Peruvians during his two years in office by working to cleanse the corrupt political establishment in Peru.