MANILA - Philippine presidential elections to be held next May are wide open and there is no clear favourite despite the son of revered former President Cory Aquino taking a strong lead in opinion polls.
  
Nominations open next week for the election and Senator Benigno "Noynoy" Aquino is likely to be among the early ones to file. Others in the fray should include billionaire businessman Senator Manuel Villar, former President Joseph Estrada and administration candidate Defence Secretary Gilberto Teodoro.
  
"There's no clear leader yet emerging," Benito Lim, political science professor at the Ateneo de Manila University, told Reuters.
  
"The campaign men are trying to create the impression that Noynoy is already far away (the winner), but that is not true."
  
Many in the business community back Villar, who controls real estate firm Vista Land and Lifescapes, although Aquino and Teodoro have their followers as well. But investors have said an Estrada victory could lead to an upheaval in markets.

The former president was ousted from office in 2001, later convicted of plunder and then pardoned by President Gloria Macapagal Arroyo. 
  
Investors have worried over his administration's profligate public spending and stories of Estrada's midnight parties with gambling and drinking buddies.

"The rags-to-riches Villar story, growing up poor and becoming a tycoon, those are the kind of things that resonate with investors and the business community," said Pete Troilo of the Political Strategies & Assessments consultancy.
  
On Estrada, he said: "You can only hope that Estrada recognises he is an illegal distraction to the official election process and does what is best for the country and steps aside, and I think nearly every foreign investor I have talked to echoes that sentiment."
  
Estrada's nomination will almost certainly be challenged since he has won a previous election as president and the Constitution allows only one term. But since he did not finish his term, the case is not clear.
  
As a former movie star with a Robin Hood image, Estrada has a large following among the poor, which has been unaffected by the scandals surrounding him.
  
"He's also a better crowd drawer than Villar," said Earl Parreno of the Institute for Political and Electoral Reforms, adding the Arroyo administration wanted him to run to take votes off Villar and Aquino and boost Teodoro's chances. 
   
Voter Surveys 
  
Aquino has led voter surveys so far, but analysts say there's a long way to go before the election. He announced his candidacy only in September, after hundreds of thousands of people poured out on the streets for the funeral of his beloved mother, Cory.

The well-regarded SWS survey, which asked respondents to name three favoured candidates last month, had Aquino with a 60 percent rating, far ahead of Villar with 37 percent. Estrada had 18 percent and Teodoro four percent.
  
"The country has very fond memories of Aquino's mother as a democracy icon but I really think you are going to start seeing other candidates chip away at that lead," said Troilo.
  
"He'd certainly be a formidable candidate, but those numbers are very, very high, based on emotions right now and they will fall."
  
Teodoro, who plans to resign from the defence secretary's post this weekend or on Monday to focus on the election, has trailed mainly because of Arroyo's unpopularity and charges of corruption against her administration.
  
But he himself is untainted and his standing is widely expected to improve, especially since the others are seen to be from the opposition and would cut into each other's votes.
  
"The two opposition candidates (Aquino and Villar) have a leg up, but you can't rule out the Arroyo political machinery that's behind Teodoro," Troilo said.