By Diego Ore and Girish Gupta

SANTA ELENA, Venezuela (Reuters) - President Hugo Chavez and opposition rival Henrique Capriles took to the provinces on Sunday to galvanize supporters and show their strengths at the formal launch of Venezuela's election campaign.

Capriles, a young state governor seeking to end 13 years of socialist rule in the South American OPEC member, was flying to two distant spots near the Brazilian and Colombian borders to highlight alleged government neglect of remote communities.

Unable to repeat the frenetic campaigning of past elections due to his struggle with cancer, Chavez nevertheless was due to make a rare appearance at a rally in central Venezuela to underline he is fit enough to run for the October 7 vote.

Chavez has a two-digit lead in most polls, but there is a large percentage of undecided voters and one respected local pollster this week put the pair head-to-head.

After three operations to remove two malignant tumors during a year-long battle with cancer, the ever-upbeat Chavez, 57, has in recent weeks declared himself in full recovery and his energy levels appear to be surging.

"My God, give us health and life to lead this people to victory!" Chavez tweeted on Sunday.

Most analysts agree the vote is shaping into Venezuela's closest since Chavez took power in 1999, turning himself into one of the world's best-known and controversial leaders with his anti-American rhetoric and radical nationalization policies.

CAPRILES CROSSES COUNTRY

Miranda state governor Capriles - a center-left politician who admires Brazil's mix of free-market economics with strong welfare policies - is widely considered the opposition's best hope after being outwitted for years by the wily Chavez.

His dash from the capital Caracas to the remote southeastern jungle community of Santa Elena, then across to La Guajira village on the western border near the Caribbean, was part of an opposition strategy to highlight the 39-year-old's energy and youth in contrast with the ailing Chavez.

"This is not just the start of the campaign," Capriles enthused, also via Twitter. "It's the countdown to opening the gate to the future for our Venezuela. Progress is coming!"

Though Venezuela's opposition is more united than ever against Chavez, Capriles still faces a formidable task to overcome the president's unique rapport with the poor and vast spending power thanks to vast oil revenues.

State media continued to bombard Capriles with insults on Sunday. Ministers lined up to call him a "loser" and "candidate of the extreme right" who would dismantle the popular missions Chavez has set up to provide free education, health services and subsidized food in poor areas.

"Chavez's whole heart is open to the people," said Girolamo Ambla, 43, dressed in the red colors of Chavez's Socialist Party and clutching a doll of the president as hundreds of supporters waited for him to appear at the town of Mariara.

Government supporters held parties and vigils across Venezuela overnight, while the opposition said it was organizing some 300 pro-Capriles caravans around the nation on Sunday.

"While the other candidate uses the TV, we will stay in the street," Capriles' campaign head Armando Briquet said, referring to Chavez's forcing of all terrestrial TV channels to broadcast many of his speeches and appearances live.

(Additional reporting by Deisy Buitrago and Andrew Cawthorne, Writing by Andrew Cawthorne; Editing by Sandra Maler)