Mexican presidential candidate Josefina Vazquez Mota of the ruling National Action Party casts her vote in Mexico City, Mexico, on July 1, 2012. Mexican voters started casting their ballots Sunday morning to choose the country's next president, 500 deputies and 128 senators in the presidential and congressional elections. (Xinhua/Miguel Tovar)

It was quite a scene as locals in Mexico City got up and went out early on Sunday to form long lines at voting booths throughout this Mexican national capital waiting for their turns to cast votes.

July 1, which fell on Sunday, was the time when general elections of Mexico, including the presidential election, started across the country.

The four candidates for Mexican presidential election --- Enrique Pena Nieto, Andres Manuel Lopez Obrador, Vazquez Mota and Gabriel Quadri de la Torre -- on Sunday also joined voters of their respective localities to cast their votes in the general elections, which are considered the largest in the history of Mexico, with 2,127 positions at stake, including the president, senators and deputies of the bicameral Congress, six governors and the mayor of Mexico City.

The four candidates are competing for the presidency in a first- past-the-post system -- the one who garners the largest number of votes wins. There is no second round of voting and no minimum percentage required for an outright win.

The first of the four candidate to cast his ballot was the candidate of the left-leaning coalition Andres Manuel Lopez Obrador in the southern Copilco district of Mexico City. Dressed in a suit and tie, Lopez Obrador arrived at his voting station as early as 8:10 a.m. local time. Like many other voters, he had to stay in a line and wait about an hour to cast his vote. Lopez Obrador counted his hope for winning the presidential election on winning the hearts of the young voters.

"The vote of the youth is going to be crucial," said Lopez Obrador just before casting his ballot.

According to the Federal Electoral Institute (IFE), 54 percent of Mexico's 80 million eligible voters are aged between 18 and 39.

The Institutional Revolutionary Party (PRI)'s Enrique Pena Nieto, who also represents Mexico's small Green Party (PVEM) and led in the latest poll with 41 percent support, voted amid both the cheers and jeers of onlookers in the town of Atlacomulco, in the neighboring State of Mexico, where he lives.

The latest poll also showed Lopez Obrador had a support of 31 percent, and Vazquez Mota with 24 percent.

The telegenic former governor of Mexico State, wearing a blazer but forgoing a tie, arrived accompanied by his second wife, actress Angelica Rivera, and their six children.

The family was quickly surrounded by party loyalists who kept nearby protesters at bay, many of them student activists.

The ruling conservative National Action Party (PAN)'s Vazquez Mota, also a resident of Mexico State, voted in the upscale residential district of La Herradura at around 9:30 a.m., accompanied by her husband and three daughters.

Vazquez Mota is Mexico's first major woman presidential candidate. Given voters in some parts of the country were afraid to go out and vote, the woman presidential candidate called on the electorate to vote, saying the military and federal police forces had been mobilized to guarantee that everything progressed "peacefully."

Gabriel Quadri de la Torre of the New Alliance Party (Panal), a fourth presidential candidate, voted in the capital's southern Coyoacan district.

Most political observers believe that Quadri's role in these elections could only secure the minimum two percent of the votes in order to ensure the Panal's existence and subsequent government financing.

The polling stations will close at 6:00 p.m.(2300 GMT) Sunday. Mexico's Federal Electoral Institute is expected to announce the quick count results of polling stations at 11:45 p.m.(0445 GMT Monday), but the official count will continue until next week.