By David Alire Garcia
MEXICO CITY (Reuters) - Mexican presidential front-runner Enrique Pena Nieto goes into Sunday's election with a clear lead over rivals, opinion polls showed on Wednesday as the campaign draws to a close.
The final voter survey of the campaign by polling firm Buendia & Laredo for newspaper El Universal showed Pena Nieto, of the opposition Institutional Revolutionary Party, or PRI, rising 4.2 percentage points to 41.2 percent from a previous poll published on June 18.
That gave him a 17.4 point lead over leftist and 2006 runner-up Andres Manuel Lopez Obrador, who rose a 0.3 percentage point to 23.8 percent, the poll showed.
Josefina Vazquez Mota, candidate of the ruling National Action Party (PAN), trailed in third place with 20.6 percent, a drop of a 0.8 percentage point from the previous survey.
Another poll published Wednesday by polling firm BGC for Excelsior newspaper put Pena Nieto's support at 44 percent of voters, giving him a 16 point lead over Lopez Obrador's 28 percent support.
The Excelsior/BGC poll had Vazquez Mota, bidding to become Mexico's first woman president, in third place with 25 percent support.
Wednesday marks the last official day of campaigning for the July 1 election as the candidates hold rallies around the country.
Recent polls also indicate the PRI could achieve a working majority in both the Senate and lower house of Congress.
That would help strengthen its mandate to push through fiscal and energy reforms that stalled under Calderon.
Lopez Obrador, the former mayor of Mexico City, lost the 2006 election to President Felipe Calderon of the PAN in a tight finish and contested the results, staging months of protests and unnerving investors in Latin America's second-largest economy.
He has stirred up fears of a repeat of the chaos this year, accusing the PRI of trying to rig the vote, though any protests would likely be short-lived if Pena Nieto wins by a wide margin.
A close result would raise the risk of fresh demonstrations, particularly given Lopez Obrador has the support of a newly-emerged student movement that shook up the campaign with huge rallies.
Mexican financial markets have already factored in a Pena Nieto win, so a close finish that puts his mandate and economic reforms at risk could spook investors and hit asset prices.
The Buendia & Laredo poll surveyed 2,000 eligible voters between June 22 and June 24. It had a margin of error of 2.5 percentage points, the newspaper said.
Excelsior/BGC said it surveyed 1,200 eligible voters between June 23 and June 25 and that its poll had a margin of error of 2.9 percentage points.
(Editing by Simon Gardner, Jon Boyle and W Simon)