GUATEMALA CITY, Guatemala (AP) — An uncomfortable challenge confronted Guatemala’s presidential candidates on Sunday: trying to win the votes of a nation that has put the last elected leader in court custody.

Most are old-guard candidates picked to run before energised prosecutors backed by a mass anti-corruption movement toppled the previous administration. Many voters are so sceptical that they campaigned for the election itself to be postponed to give them a new crop of choices.

Leading in most polls with roughly 30 per cent backing is Manuel Baldizon, a wealthy 44-year-old businessman and long-time politician. His running mate is accused by prosecutors of influence trafficking, but as a candidate enjoys immunity from prosecution.

Guatemalans began heading to the polls after they opened early Sunday to also elect a vice president, members of Congress and the Central American Parliament, and local authorities for 338 municipalities nationwide.

In the presidential race, Baldizon’s most competitive rivals were television comedian Jimmy Morales, who has never held elective office, former first lady Sandra Torres and Zulia Rios, the daughter of a former dictator accused of genocide.

If none of the 14 candidates reaches 50 per cent, a run-off will be held October 25.

A key question is the level of protest vote in the face of a corruption scandal that has forced President Otto Perez Molina and Vice President Roxana Baldetti to resign. Both are currently in custody, accused of being involved in a customs kickback scheme.

Activists are urging voters to go to the polls wearing black clothes of mourning, abstain or cast null ballots. On the streets, it’s hard to find a campaign poster that hasn’t been covered with insults. Tens of thousands had joined demonstrations asking for the vote to be postponed.

Baldizon, who finished second in the last presidential race, initially campaigned on the slogan “It’s his turn” — a reference to the fact that the last four elections have been won by the previous runner-up. It struck many critics as a display of what’s wrong with the country’s politics. At protests, demonstrators have chanted: “It’s not your turn.”

Baldizon has acknowledged Guatemalans’ disgust with crime, corruption and impunity. His campaign website vows a “modernization of the democratic state” to reform government and combat poverty and social inequality.

But after Baldizon’s campaign blew past the legal ceiling on electoral costs, he ignored orders to stop spending.

Morales, 46, boasts of his outsider status and says he is part of the uprising against corruption. He has promised greater transparency, including media review of government contracts.

Torres, 59, divorced former President Alvaro Colom ahead of the last presidential race to try to get around rules barring presidential relatives from running, but was still ruled ineligible. A businesswoman and long-time political party figure, she is proposing a coalition government to respond to the concerns of outraged citizens.

Rios, 47, is the daughter of former dictator Efrain Rios Montt, who faces charges of crimes against humanity for killings by security forces during his 1982-83 regime. She emphasises her experience from 16 years in Congress, where she promoted laws against discrimination and drug and human trafficking.