Peruvians go to the polls on Sunday hoping to break a cycle of instability that has produced nine presidents in a decade as well as surging violent crime, corruption scandals and overwhelming distrust in institutions and politicians.

About 27 million people who are eligible to vote must choose between a record 35 presidential candidates as well as contenders for the bicameral congress – all from a ballot sheet measuring nearly half a metre, the longest in the country’s history.

The fight against crime tops voter concerns amid record homicide and extortion rates but political corruption comes a close second. Four former presidents are in jail, most of them linked to bribery cases involving the Brazilian construction company Odebrecht.

Keiko Fujimori, a three-time presidential candidate and the daughter of the late president Alberto Fujimori, holds a narrow lead in opinion polls. She is closely followed by the comedian Carlos Álvarez and two former mayors of Lima, the ultra-conservative Rafael López Aliaga and the media mogul Ricardo Belmont.

None of the candidates is polling above 15%, making a runoff on 7 June almost certain, according to Urpi Torrado, of the polling company Datum Internacional.

“This is one of the most unpredictable elections on record,” said Torrado. “There could be surprises this Sunday because we don’t know who will make it through to the second round.”

Fujimori, 50, is making her fourth bid for the presidency, having reached the runoff in the last three elections (2021, 2016 and 2011) and losing by extremely narrow margins each time. The rightwinger served as first lady in the autocratic 1990s government of her late father, who was convicted over corruption and human rights abuses and spent 16 years in prison.

Ricardo Belmont, who was Lima’s mayor from 1990 to 1995, has risen in most opinion polls, winning the younger vote with his upbeat messaging and the slogan “hugs not bullets”, borrowed from the former Mexican leader Andrés Manuel López Obrador.

Gonzalo Banda, a Peruvian political analyst and doctoral researcher at University College of London’s Institute of the Americas, called Belmont an “anti-establishment candidate catching votes from the right, the left and the centre”. The 80-year-old is also known for making xenophobic and sexist remarks.

López Aliaga, who was Lima’s mayor until a few months ago, has run a hard-right campaign littered with disinformation, hate speech and threats against journalists and opponents. But the 65-year-old rail magnate, who has opposed same-sex marriage and pledged to refuse abortion to underage rape victims, has slipped in the polls.

The surprise entry is Álvarez, one of Peru’s best-known comedians, who has been imitating presidents for the last three decades. However, his proposals are far from lighthearted. He describes himself as an admirer of Donald Trump and El Salvador’s leader, Nayib Bukele, and his tough-on-crime campaign has focused on megaprisons and the death penalty.

“It is ironically poetic that due to this cycle of [political] decay in Peru, we could end up with a comedy performer who imitates politicians as president,” said Banda.

Other candidates include Roberto Sánchez, who has been endorsed by the ousted former populist leader Pedro Castillo and wears the same style of wide-brimmed sombrero. Centrist candidates include a former defence minister, Jorge Nieto, and a former university rector, Alfonso López Chau.

Torrado said: “No political leader has emerged who can generate a sense of hope, a feeling that this person could change the country’s political course or solve its problems. Peruvians feel that in recent years, politicians have turned their backs on the people.”