Keijo Fujimori, Peru presidential candidate, cancels appearance as thousands protest

Tens of thousands of Peruvians marched against presidential front-runner Keiko Fujimori Tuesday on the anniversary of her authoritarian father's most infamous power grab - forcing her to suspend campaign events ahead of Sunday's elections.

Protesters chanted "Never again!" and said a vote for centre-right Fujimori would be a vote for ex-president Alberto Fujimori, who is now serving a 25-year sentence for human rights abuses and corruption committed during his 1990-2000 government.

At least 30,000 took part in the protest in Lima - a sign of the stiff opposition to Fujimori that could make her vulnerable to defeat in a run-off. Fujimori is expected to win the biggest share of votes on April 10 but not the simple majority needed to win outright.

Many demonstrators derided Fujimori's recent promise to never repeat her father's "self coup" on April 5, 1992, when he order the military to shutter Congress and intervened in the courts. Fujimori had previously defended the move as needed to enact economic reforms.

"I don't believe her at all," said Rodolfo Lazo, a 19-year-old university student who had painted "I'm young but I'm not stupid" on his T-shirt.

Protesters also criticized the country's electoral board for clearing Fujimori of allegations that she broke a law against vote-buying while disqualifying two leading rivals. "National Jury of Elections, National Shame!" one sign read.

Fujimori cancelled her public appearances and told her supporters to suspend campaign activities on Tuesday ahead of the rallies, which were scheduled in cities across Peru.

Her political party called for tolerance on Twitter and posted pictures of campaign offices in different towns covered in banners that read "No More Violence."

The protest in Lima was peaceful. Smaller rallies outside of the capital have ended with clashes and opponents have pelted eggs at Fujimori during campaign events.

The demonstration on Tuesday was the biggest political protest in Lima since massive rallies against Alberto Fujimori in 2000 as he tried start a third term following elections widely considered fraudulent.

Fujimori had set out early in her campaign this year to distance herself from her father after narrowly losing her first presidential bid to President Ollanta Humala in 2011. But 45 per cent of Peruvians say they will definitely not vote for her - higher than her two closest rivals, leftist lawmaker Veronika Mendoza and investor-favorite Pedro Pablo Kuczynski, according to the most recent Ipsos poll.

Humala cannot seek a new term because of constitutional limits.