Presidential candidates begin official campaigning for what has been dubbed ‘the biggest election in Mexican history’.

The official campaign season for the Mexican presidency kicks off on Friday, with four candidates vying for the position.

For the next 90 days, presidential candidates Margarita Zavala, Andres Manuel Lopez Obrador, Ricardo Anaya, and Jose Antonio Meade will do their best to win the hearts and minds of approximately 88 million registered Mexican voters.

Here is what we know so far:

1) When are the Mexican elections taking place?

The Mexican elections are scheduled to take place on July 1, 2018.

Voters will elect a new president to serve a six-year term, 500 members of the Chamber of Deputies and 128 members of the Senate.

2) Who are the candidates?

Andres Manuel Lopez Obrador: He is the candidate for the coalition Juntos Haremos Historia (Together we will make history), and he is representing the National Regeneration Movement (MORENA).

He chose Ciudad Juarez as the site to kick off his third campaign for the presidency. He ran and lost by a close margin Mexico’s last two presidential elections in 2006 and 2012.

If elected, he promised to review oil contracts with other countries and has also expressed doubts over the future of NAFTA.

This year, opinion polls show Lopez Obrador with a large lead. Many describe him as a left-winger and a populist, which could affect the country’s economy, but many others believe he represents a real alternative.

Presidential candidate Andres Manuel Lopez Obrador of the MORENA party speaks after formalising his candidacy at the National Electoral Institute in Mexico City, Friday [Eduardo Verdugo/AP]

Ricardo Anaya: He is the candidate leading the Por Mexico al Frente alliance (For Mexico in Front), and is representing the PAN (National Action Party). He has scheduled the first event of his campaign in Mexico City.

He is the candidate leading the Por Mexico al Frente alliance (For Mexico in Front), and is representing the PAN (National Action Party). He has scheduled the first event of his campaign in Mexico City. According to some opinion polls, Anaya is in second place. He describes himself as a modern alternative to the unpopular ruling party, the Institutional Revolutionary Party (PRI) and to Lopez Obrador.

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

Presidential candidate Ricardo Anaya of the Forward for Mexico Coalition gestures to young supporters during his campaign kick-off event in Mexico City [Rebecca Blackwell/AP]

Jose Antonio Meade: is Mexico’s former finance minister and is running as the candidate for the Todos por Mexico (Everyone for Mexico) coalition and represents the PRI, which is currently in power; according to his website, he has chosen the city of Merida as the starting point for his campaign.

is Mexico’s former finance minister and is running as the candidate for the Todos por Mexico (Everyone for Mexico) and represents the PRI, which is currently in power; according to his website, he has chosen the city of Merida as the starting point for his campaign. The PRI is facing a loss of credibility, with current President Enrique Pena Nieto’s approval rating at 17 percent, since January.

PRI candidate Jose Antonio Meade has admitted in his campaign that political parties are mistrusted, but says he is in the right place to capture the mood; according to opinion polls, he is currently in third place.

Mexico’s former finance minister and currently the candidate for the coalition Everyone with Mexico Jose Antonio Meade gives a speech [Henry Romero/Reuters]

Margarita Zavala is the only candidate running as an independent.

Zavala is the wife of former Mexican President Felipe Calderon, a man who ran and won against Lopez Obrador in 2006.

Zavala split with Calderon’s party, PAN, and decided to run on her own. This is the first time an independent candidate will appear on the presidential ballot.

Her campaign began just after midnight on Thursday, March 29 at the Angel de la Independencia in Mexico City.

Former first lady and independent presidential candidate Margarita Zavala addresses supporters during a rally at the start of her electoral campaign in Mexico City [Eduardo Verdugo/AP Photo]

3) Why are these elections important?

These have been described as “the biggest election in Mexican history” according to the National Electoral Institute (INE) due to the number of public issues being debated. On the same day. 30 out of 32 states will also hold local elections.

This election will redefine the role of the government in areas such as economic development, trade, security and energy.