By Adriana Barrera and Michael O'Boyle
MEXICO CITY (Reuters) - Days before Mexico's presidential election on Sunday, the two mainstream candidates remain mired in a knock-down fight to be the second-place challenger to the anti-establishment favourite, hoping they can mount a last-minute surge.
For months, instead of focusing attacks on Andres Manuel Lopez Obrador to diminish his double-digit lead, both Ricardo Anaya, of a right-left coalition, and the ruling party's Jose Antonio Meade have targeted firepower on each other.
There is method to the apparent madness - in Mexico there is no run-off vote despite a multi-party system and second-placed candidates often rapidly gain ground in the final weeks of campaigning as voters tactically switch from obvious losers to stop their least favourite.
While third-time candidate Lopez Obrador has broadened his appeal during this campaign with a big tent approach and soothing words for markets, many Mexicans still see him as a populist who will unwind decades of free-market economic reforms in Latin America's No. 2 economy.
Those are voters both Meade and Anaya are trying to draw into their camp in the final hours of the campaign.
"I will vote for whichever candidate who, even if they are not my favourite, can prevent the country from falling into the hands of populists manipulating fear," said 70-year-old Guadalupe Rivero, a retired publicist.
But unlike other recent elections in Mexico, neither Anaya or Meade has broken away in opinion polls, leaving them in a technical tie, bogged down by mutual accusations of corruption and crony capitalism.
LOCK HIM UP
Just last week, Mexico's political rumour mill was in overdrive ahead of a news conference by Anaya's campaign.
Many were expecting the 39-year-old to follow up on allegations of crony capitalism against Lopez Obrador he made during the last debate.
But, instead, his team said they were demanding an investigation into Meade for signing contracts given to a unit of Brazilian engineering firm Odebrecht, which is embroiled in corruption charges in several countries. Meade denies wrongdoing.
Leading an alliance between his National Action Party (PAN) and the centre-left Party of the Democratic Revolution (PRD), Anaya has sought to capitalize on public anger over corruption.
He has painted himself as an "intelligent change" in contrast with what he says are Lopez Obrador's outdated ideas. At campaign events that look like Silicon Valley product launches, he pledged to transform Mexico from a manufacturing-based economy by creating "knowledge-based" jobs.
"This election is between just two: between Ricardo Anaya and Andres Manuel Lopez Obrador. And the people know that," said Salomon Chertorivski, Anaya's top economic adviser.
However, growing momentum behind Anaya early this year was derailed by reports of an investigation by authorities into alleged money laundering surrounding a land deal by Anaya in his home state of Queretaro.
"They were very effective attacks," said Guillermo Valdes, from political consultancy GEA.
Anaya denied any wrongdoing, and, accusing the government and Meade of a smear campaign, went on the counter attack.
He moved to out-do Lopez Obrador's anti-corruption platform by pledging to set up a truth commission to investigate graft during Pena Nieto's administration.
During the final TV debate in June, Anaya turned to Meade, saying: "With all that you and the government have invested in false news, in attacking me, maybe you can convince people."
"But let it be very clear: if you do not succeed and I'm president, you're going to face justice."
Former Finance Minister Meade was chosen by the ruling party as a clean face to head its re-election bid.
Having served in the cabinet of President Enrique Nieto and his PAN predecessor Felipe Calderon, Meade is respected by the technocrat wings of both parties.
Meade is not a member of the PRI, and he has projected himself as irreproachably honest and the only candidate capable of maintaining hard-won economic stability.
His early campaign failed to ignite when he embarked on a tour of PRI strongholds, cosying up with leaders synonymous with allegations of corruption that have dogged the party.
After months in third place, recent polls show him gaining some ground and being technically tied with Anaya. PRI leaders insist that their party is Mexico's only national force with a well-oiled machine that can turn out the vote.
Meade is mounting "a last-minute surge that has an outside, but real chance of winning," said Luis Madrazo, a senior member of Meade's campaign.
(Reporting by Adriana Barrera and Michael O'Boyle; Additional reporting by Veronica Gomez; Editing by Frank Jack Daniel and Lisa Shumaker)