MEXICO CITY (Reuters) - Mexican presidential candidates on Friday kicked off a three-month race to the election with pledges to transform an entrenched corrupt political system.

Ricardo Anaya, presidential candidate for the National Action Party (PAN) greets supporters next to his wife Carolina Martinez and members of his left-right coalition during his kick-off presidential campaign in Mexico City, Mexico March 30, 2018. REUTERS/Carlos Jasso

Two of four presidential hopefuls launched their campaigns just after the midnight starting gun for the countdown to Mexico’s July 1 vote, tapping into disapproval over corruption scandals under the ruling party that has governed for most of the past century.

Voter anger so far favors leftwing dissenter Andres Manuel Lopez Obrador, 64, who will launch his own anti-corruption focused campaign on Sunday and holds a double digit lead in most polls.

Second-place contender Ricardo Anaya, 39, running for the right-left coalition “For Mexico in Front”, launched his campaign just after midnight on Friday, hosting a hackathon for 1,000 youths to work together on technology-driven ideas to combat corruption and violence.

“Mexico is going to change,” Anaya told the crowd of cheering young people. “This corrupt government has its days numbered.”

Kickbacks and pilfering that undermine public services, believed to cost Mexico billions of dollars each year, have emerged as the main campaign issue.

All the candidates vow a clampdown, with measures including removing immunity for the president and creating a truth commission to study past crimes.

Anaya has pitched himself as a forward-thinking alternative both to the unpopular PRI and Lopez Obrador’s personalized leadership.

A Lopez Obrador government could mark a change in direction for Mexico, with a less accommodating approach to the United States and a more cautious view of foreign investment. He has pledged to closely study billions of dollars of energy and infrastructure contracts.

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Critics have said uncertainty surrounding his policies will choke business, while Lopez Obrador says uncertainty is better than turning a blind eye to corruption.

Monica Vargas, a 22-year old literature student from the central state of Tlaxcala, said she supported Anaya because he was listening to young people. She said many of her schoolmates had dropped out of college due to lack of funds.

“As a Mexican I feel very disappointed... we realize how rich our public officials have become, and we the people are always lagging behind,” Vargas said.

Former first lady Margarita Zavala, in fourth place in the polls and the only independent to land enough certified voter signatures to qualify for the ballot, also kicked off her campaign in the capital, taking aim at what she said was dishonesty among her rivals.

“We have three candidates who represent the snare of money in politics, the politics of corruption,” she told supporters at the famed Angel of Independence monument.

Mexico saw a record number of killings last year as organized crime gangs smuggled drugs, fuel and people while corruption scandals hit the credibility of President Enrique Pena Nieto’s Institutional Revolutionary Party (PRI).

The centrist PRI has ruled Mexico continuously since 1929, except for a 12-year break when Vicente Fox and his successor led the National Action Party (PAN) to power in 2000 and 2006.

Variously described as a left-winger, a populist and a nationalist, Lopez Obrador quit the PRI in the 1980s. His subsequent political career included a stint as mayor of Mexico City, one of the world’s largest metropolises.

The campaign of PRI candidate Jose Antonio Meade, 49, a five times minister who is not a PRI member and has served under a PAN administration, concedes that political parties are deeply mistrusted but says he is best placed to capture the anti-corruption mood. His Sunday campaign launch will emphasize vows to fix problems without undoing economic progress.

For many voters, July 1 will be about rejecting either the corruption of the ruling party, or Lopez Obrador, said PAN Senator Ernesto Ruffo, backing Anaya.

“This is an election not for, but against,” he said.