Can Chavez keep the red flag flying?

Hugo Chavez, the firebrand socialist ruler, may be losing his battle against cancer. David Usborne asks what comes next for Venezuela

Hugo Chavez thrives on drama. After coming to power 13 years ago, the former military officer has survived a coup, likened an American president to the devil and used a combination of charisma and oil revenues to sweep away all serious opposition. But today his raging invincibility is in doubt.

It isn't only that ahead of elections in October, the opposition in Venezuela has settled on a candidate who, though still far behind in the polls, is showing signs of strength. There is another matter weighing more heavily than any other: the recurrence of cancer that was first diagnosed last year.

Today, Venezuelans will wake up knowing that their President is in Cuba, the country where he has chosen to receive treatment, including ongoing radiation therapy and, to date, three operations. The first last June involved removing a tennis-ball sized tumour from his pelvic area. According to the opposition, Mr Chavez has spent almost three of the last twelve months in Cuba.

With characteristic bluster, Mr Chavez has repeatedly vowed to defeat the disease. The setbacks are beginning mount up, however. He declared himself free of cancer at the end of last year only to be told in February it was back. He returned from Cuba to Caracas last Wednesday after one round of radiation only to return to the island again on Sunday. He is scheduled to remain there all of this week.

Any reference to his illness comes with the usual theatrics. "Give me life, even if it is a burning, painful life, I don't care," he pleaded at an Easter mass. "Give me your crown, Jesus. Give me your cross, your thorns so that I may bleed. But give me life, because I have more to do for this country and these people."

He made sure to be in Venezuela at the end of last week for celebrations marking his return to power after the brief coup 10 years ago. Addressing crowds clad in red T-shirts to honour the socialist revolution he has led, he again returned to the topic. "The radiation has an impact on my body, it has some impact on my physical strength, but I am doing well. We will be all right, thank God," he said.

It is a measure of the seriousness of his condition that Mr Chavez opted to skip the Summit of the Americas in Colombia at the weekend, a stage he has previously used to lob rhetorical grenades at Washington. While it was George W Bush who received the devil moniker back in 2006 during a UN General Assembly, the love has been no less absent between Chavez and Barack Obama.

It is now a serous question as to whether Mr Chavez will have it in him to fight the election effectively. He has built an image of an indefatigable, hands-on leader, who works around the clock, delivers speeches that last hours (he broke his own record in January with a 10-hour address) and has laid no visible succession plans. If that presence begins to shrink, voters could begin to turn away.

A lesser ego might surrender to medical counsel and retire. "I think Chavez will hang on until he is incapacitated or dead," Professor Gregory Weeks, director of Latin American studies at the University of North Carolina said yesterday, while noting that the President's health issues are "clearly serious".

"For Chavez, being President is not a 9-5 job. It's a mission, almost a religious vocation," noted a US biographer of the president, Bart Jones. "His life's work is at stake and it would mean too much for him to take a step back."

The man set to benefit from a weakened Mr Chavez, politically and physically, is the opposition leader Henrique Capriles, who at 39 has already set a dizzying pace campaigning across the land on a platform that promises to shed the extremes of the socialist regime.

The most recent poll has put Mr Capriles 13 points behind and Mr Chavez, aside from controlling most of the media, has set about dispensing $26bn to build homes for the poor and give cash to the elderly. But by offering an alternative that might be called Chavez-lite, Mr Capriles may have a chance to make up the gap. "Capriles is trying to appeal to the left and this could definitely pick up votes," predicts Professor Weeks.

And while his over-sized personality and generous state subsidies from oil-fed coffers have worked well for Mr Chavez in the past, voters this time may take heed of the country's mounting problems, including rampant inflation and its record as one of the most violent countries in the Americas.

The opposition is seeking to exploit the absences in Cuba as well as the mystery around the President's illness. The precise nature of the cancer and – crucially – whether there has been any sign of it spreading to other organs has yet to be explained. "In the past 340 days, the President has spent 200 days in recovery and 80 days in Cuba," the opposition member Carlos Berrizbeitia said in Congress recently, adding: "Venezuelans are learning about the President's health from rumours."

The polls have also indicated that, five months from the election, many Venezuelans remain undecided. Just as Mr Chavez faces a diminution of vigour, the younger Mr Capriles is brimming with it, riding a motorbike on the campaign trail and playing basketball.

At the celebrations of the reversal of the coup of April 2002, Mr Chavez did his best to put down the opposition. He predicted he would win "by a knock-out". He added: "It would be easier for a horse to go through the eye of a needle than for the opposition to win the elections." He recently also threatened also to privatise banks he saw as supportive of the opposition. "We will make them repent for ever," he said.

This is the kind of bullying and bravado we have come to expect from Mr Chavez but if the pugilism grows any louder it might be because of the writing he sees on the wall of his doctors' consulting rooms.

The rise of Chavez: Path to power

February 1992 Chavez, then a 37-year-old army officer, leads a failed coup against President Carlos Andres Perez.

December 1998 Riding a wave of discontent over alleged state corruption, Chavez – pardoned and freed from jail four years earlier – leads his party to election victory.

April 2002 A coup removes Chavez from office for a few days, but army loyalists return him to power.

December 2006 The President wins another six-year term.

June 2011 Chavez says he has cancer and goes to Cuba for treatment.