Thousands of people took part in protests in cities across Mexico over the weekend under the banner of the "Yo soy 132" student movement, rejecting the candidacy of presidential frontrunner Enrique Peña Nieto, of the Institutional Revolutionary Party, or PRI.

Sunday's protests took place hours before Mexico's four presidential candidates participated in the last debate before the July 1 election.

Some 40,000 people, mainly young people, took to the streets of Mexico City, marching from the Zocalo, the capital's main plaza, to the Angel of Independence monument in what organizers labeled the "Second National anti-Peña Nieto March."

The PRI governed Mexico without interruption from 1929 to 2000, a regime described by Nobel Prize-winning novelist Mario Vargas Llosa as "the perfect dictatorship."

The PRI era ended with the election in 2000 of the conservative National Action Party's Vicente Fox, who was succeeded six years later by fellow PAN member Felipe Calderon after the closest presidential contest in Mexican history - which the runner-up, leftist PRD party candidate Andres Manuel Lopez Obrador, maintains was marred by fraud.

Peña Nieto's frontrunner status in the presidential race is due, in part, to Mexicans' frustration over persistently high levels of drug-related violence throughout Calderon's term.

The march drew students, workers and housewives, with some women taking their children along.

The protest movement started on May 11, when Peña Nieto visited the Universidad Iberoamericana and was jeered by students, who accused him of being a candidate "manufactured" by the powerful Televisa network.

Those in Peña Nieto's inner circle and some media pundits downplayed the incident, accusing the students of being agitators.

The students counterattacked by making a video that was posted on YouTube.

The criticism led to the birth of the "Somos mas de 131" (We Are More Than 131) movement, which took its name from the number of students who appeared in the video and later evolved into the "Yo soy 132" (I Am 132) movement when students from other universities joined the protests.

The young people also created the Twitter hash tag #LaMarchaYoSoy132 to get their message out to supporters and the public.

One of the main demands made by the non-partisan student movement is that Mexico's media be democratized and provide balanced coverage.

Groups from the National Autonomous University of Mexico, or UNAM, and the National Polytechnic Institute took part in Sunday's march along with students from other private and public universities.

The activists should slogans such as "Queremos escuelas, no telenovelas!" (We Want Schools, Not Soap Operas) and "Fuera Peña, fuera Peña!" (Out Peña, out Peña!).

Other marches against Peña Nieto took place in Monterrey, Guadalajara, Acapulco, Oaxaca, Puebla, Queretaro, Toluca, Tuxtla, Cancun and Cuernavaca, among other cities. EFE