MEXICO CITY –  Mexico's leftist presidential candidate said Friday that while he plans to lead campaign to annul the results of the July 1 elections, he ruled out the use street blockades and protest camps.

Leftist Andres Manuel López Obrador, who was second in the July 1 elections, said he will hold mass rallies and pursue legal challenges up to the Sept. 6 deadline for electoral courts to rule on the validity of the results.

He claims the winner, Enrique Peña Nieto of the old ruling Institutional Revolutionary Party, engaged in massive vote-buying and campaign overspending. Peña Nieto's party has denied those allegations and said López Obrador simply refuses to accept his defeat.

In 2006, López Obrador lost the presidency by a much smaller margin, and led weeks of street blockades in Mexico City to protest what he claimed had been vote fraud.

Our adversaries would like us to fall into the trap of provocation and violence, but they are not going to get their wish.

- Mexican presidential candidate Andres Manuel López Obrador

But this year, López Obrador said, "the circumstances are different."

He said that, at least until the electoral court rules, his self-described "National Plan to Protect Democracy and Mexico's Dignity" will hold rallies on July 29 and August 5, and artistic events.

"We are going to use peaceful methods," López Obrador said. "Our adversaries would like us to fall into the trap of provocation and violence, but they are not going to get their wish."

"We do not want to give the violent ones a pretext to call us violent."

López Obrador says the country's electoral watchdog agency has taken the side of Peña Nieto, who won the race according to official vote counts.

López Obrador said Friday the country's Federal Electoral Institute "is turning a blind eye" to alleged campaign overspending and vote-buying by Peña Nieto.

The institute's president said his agency's investigative team has until January to finish its probe, by which time Peña Nieto would already have been sworn into office.

López Obrador called that "ridiculous" and demanded the investigation be finished before Peña Nieto is officially recognized as the winner.