MEXICO CITY (Reuters) - Leftist Andres Manuel Lopez Obrador leads by 13.6 percentage points in the run-up to Mexico’s July 1 presidential election and has an even bigger advantage over the ruling party candidate, a voter survey by polling firm Ipsos showed on Thursday.

FILE PHOTO: Mexican presidential pre-candidate Andres Manuel Lopez Obrador of the National Regeneration Movement (MORENA) greets supporters during a pre-campaign rally in Queretaro, Mexico February 9, 2018. REUTERS/Henry Romero/File Photo

The opinion poll seen by Reuters showed two-time runner-up Lopez Obrador, a former mayor of Mexico City, garnering 36.3 percent support in the election.

Running second on 22.7 percent was Ricardo Anaya, a onetime leader of the center-right National Action Party (PAN), who fronts the challenge of a right-left coalition.

Back in third, on 15.1 percent, was former finance minister Jose Antonio Meade, the candidate of President Enrique Pena Nieto’s Institutional Revolutionary Party, or PRI.

The Ipsos survey is the latest of several opinion polls to show Lopez Obrador in a strong position ahead of the start of formal campaigning on March 30. He finished second in 2006 and 2012.

The 64-year-old founder of the National Regeneration Movement (MORENA) party has capitalized on disaffection with the PRI over a slew of political corruption scandals, increasing gang violence and sluggish economic growth.

Meade, who is not formally affiliated to any party, has so far struggled to gain traction in a race being run in the shadow of strained relations between his government and U.S. President Donald Trump, who has frequently criticized Mexico.

The poll was the first conducted by Ipsos since the three main contenders were formally chosen as candidates last month.

It had a margin of error of 2.53 percentage points and consisted of 1,500 face-to-face interviews carried out nationwide between Feb. 24 and March 3, Ipsos said.

The poll also suggested that many voters may still be up for grabs, with almost 22 percent of the respondents surveyed either rejecting all contenders, or giving no answer.

In addition, independent hopeful and former first lady Margarita Zavala had around 2.8 percent support, with two other independents polling a combined 1.5 percent between them.

Trump has riled Mexicans by insisting the country will pay for a border wall he wants built to keep out illegal immigrants, and by threatening to dump the North American Free Trade Agreement, a cornerstone of Mexico’s business model.

A separate survey by polling firm Parametria published on Wednesday showed Lopez Obrador widening his lead over Anaya to 14 points, with Meade also losing ground.

(This version of the story corrects to show percentage of voters not backing a candidate almost 22 percent instead of more than 32 percent after Ipsos corrected its figure, paragraph 10)