President Martin Vizcarra faces an impeachment trial in congress Friday after Peru's top court rejected his government's appeal to block the vote, though analysts said he would likely survive.

The Constitutional Court ruled by five votes to two to allow the vote, its president announced in a statement which acknowledged that in any case, Vizcarra's removal appeared increasingly remote.

Analysts said his opponents in congress are likely to fall short of the 87 votes needed to oust him when the 130-member chamber meets on Friday morning.

Congress voted last week to open impeachment proceedings against the 57-year-old president for "moral incapacity" over accusations he incited aides to lie to anti-graft investigators.

Vizcarra's cabinet petitioned the Constitutional Court this week on the grounds the legislature had exceeded its powers and was not competent in seeking to rule on the president's moral capacity.

However Ledesma said the seven-member court "has decided to admit the competency claim to proceedings" but pointed out the ruling in that case would take several weeks.

Ledesma said that meanwhile, "in light of the declarations of political leaders, the risk of vacancy (of the office of president) has been weakened and there is no manifest urgency."

The president's main rival, Keiko Fujimori, had publicly acknowledged that "there are not enough elements" to remove him from power.

Vizcarra, accompanied by his lawyer for the proceedings, will address the unicameral Congress before what is expected to be a lengthy debate.

Most of the opposition parties in the fragmented legislature said they would not vote en bloc.

Peru's President Martin Vizcarra faces an impeachment trial over accusations of "moral incapacity Peru's President Martin Vizcarra faces an impeachment trial over accusations of "moral incapacity" Photo: AFP / Ernesto BENAVIDES

Public support for the president has been evident in opinion polls, social networks and pot-banging street protests.

Eight out of 10 Peruvians want him to continue until the end of his mandate in July 2021, according to an Ipsos poll.

Business leaders called on political leaders to show unity in order to face the economic and health crisis, while influential Catholic leader Cardinal Pedro Barreto said removing the president now would be "catastrophic" for the country.

"The bulk of the population would basically just like to turn the page on this incident," said analyst Carlos Requena.

"Nobody wins here: the executive and the congress both lose. People see two branches of the State engaged in a political struggle while a pandemic is killing Peruvians amid terrible unemployment, that will take five years to recover from," another analyst, Augusto Alvarez Rodrich, told AFP.

The South American country has the world's highest per-capita death rate from the coronavirus, with more than 31,000 deaths and nearly three-quarters of a million cases.

"Politicians should focus on other, much more important things, such as how the nation faces up to the economic situation and the pandemic," self-employed David Gonzalez, 53, told AFP.

"It's stupid what they're doing right now," said Cristian Zapata, a 29-year-old Lima businessman.

Pressure on Vizcarra appeared to ease already on Tuesday when his star economy minister, Maria Antonieta Alva, survived a censure motion in congress.

He had begun the week pushing back against his opponents, going on television to insist he was victim of a conspiracy after an anti-corruption crusade that has put him and his minority government at loggerheads with congress.

Vizcarra's four predecessors have all been investigated for corruption.

Vizcarra succeeded Pedro Pablo Kuczynski in March 2018 after he resigned ahead of an impeachment vote brought after he became embroiled in the giant Odebrecht scandal.