CARACAS (Reuters) - Venezuela's President Hugo Chavez declared himself fully recovered from cancer on Monday, three months before an election in which he is seeking another six-year term.

"Free, free, totally free," he told reporters when asked if he was free of the disease that struck a year ago.

The 57-year-old socialist leader was first diagnosed with cancer in the pelvic region in mid-2011. He wrongly declared himself cured at the end of that year before having a recurrence of the disease in February.

But after repeated cycles of treatment in Cuba and Venezuela, Chavez is once again declaring himself fully fit at a crucial time when his health is the main wild card before the October 7 presidential vote.

Perceptions of Chavez's ability to campaign for the election, and govern afterwards, are crucial among voters in what could be one of Venezuela's tightest elections of recent times.

At a four-hour news conference that offered more evidence of Chavez's increasing energy levels, he promised to begin campaigning on the streets with a series of caravans in provincial Venezuela from Thursday.

"Now is when I'm stepping into the action. Our offensive begins right now!" said an ebullient Chavez, who disappeared for long periods during treatment over the last year but has been back dominating Venezuela's airwaves in recent weeks.

"Chavez is back in the street, the Bolivarian hurricane!" he added, referring to his spiritual idol and Venezuela's independence hero, Simon Bolivar.

Despite Chavez's optimism, doctors say it is impossible to be sure someone is completely cured until at least a couple of years have passed since the last recurrence of cancer.

The former soldier is leading most opinion polls by double digits, but one recent survey put him neck-and-neck with opposition candidate Henrique Capriles and up to a third of voters remain undecided.

Capriles, a 39-year-old, center-left former governor, has been criss-crossing Venezuela on a "house-by-house" tour in a show of youth and energy that the opposition has been using to contrast with the ailing Chavez, 57.

The president, though, who was famous for his whirlwind on-the-street campaigning of the past, appears to be recovering his energy levels just in time.

"Every day, I feel in better physical condition and I strongly believe ... it is not going to be a determining factor in this campaign," he told reporters. "I'm a veteran of 100 battles and I feel in great moral, spiritual and physical conditions for this fight that is starting."

(Writing by Andrew Cawthorne; Editing by Philip Barbara)