LIMA, Peru — Vicenta Escobar, 62, sells fruit from a stand on the streets in Peru’s capital, Lima. In every presidential election over the last four decades, she has chosen a candidate she believed in, in the hope that he or she would deliver change.

Not this time, though. This Sunday, she plans to arrive at her polling station to vote — as is required by Peruvian law. But she will cast her ballot without making a single mark.

“I’m planning on leaving it blank,” she said on Thursday afternoon. She was fed up, she said, with “all the lies and robberies.”

Peruvians are voting on Sunday at a moment many are calling one of the lowest points in the country’s young democracy. Eighteen candidates are on the ballot, but about 15 percent of voters are expected to cast a blank vote, according to several recent polls, and no candidate has been able to garner much more than 10 percent support. The leading two candidates will advance to a runoff if no one captures more than half the vote.

of the highest coronavirus death rates in the world, and daily deaths climbed to new highs this month as the Brazilian variant of the virus spread through the country. Many Covid patients have died amid lack of access to oxygen or ventilators, working-class families are struggling to secure enough food, and school closures have pushed children into the labor force.

The economy shrank 12 percent last year in the country’s worst recession in three decades — the second-worst downturn in Latin America, after Venezuela’s.

Voters interviewed this month in Lima, the capital, appeared to coalesce around their shared frustration with the system.

he had been secretly vaccinated last year with extra doses from a clinical trial in Peru that researchers distributed among political elites.

according to a 2018-2019 survey by the Latin American Public Opinion Project, with the military seen as the most trustworthy institution.

Since the last general election produced a divided government five years ago, Peru has seen constant clashes between the legislative and executive branches, as opposition lawmakers have sought to impeach two presidents and Mr. Vizcarra dissolved Congress, calling new legislative elections to push through reforms.

Three former presidents have spent time in jail during bribery investigations, including one candidate in this year’s election; a fourth killed himself to avoid arrest; and a fifth, Mr. Vizcarra, one of the most popular recent leaders, was impeached in November.

His replacement, who lasted less than a week in office, is under investigation in connection with the fatal shootings of two young men at protests, which led to his resignation.

One reason for the country’s endemic corruption is that political parties often barter their loyalties to presidential candidates in back-room deals, and are often captive to special interests.