Hugo Chávez, the radical Venezuelan President, has finally met his match. Henrique Capriles, whose grandparents fled Nazi persecution during the Second World War, is the first opposition candidate to have a serious chance of ousting Mr Chávez since he came to power 13 years ago.

So concerned is the left-wing Venezuelan government about Mr Capriles that Mr Chávez has resorted to personal insults - repeatedly calling him "a pig" - and state media has attacked his Jewish roots, branding him a representative of the "Zionist enemy that threatens to destroy the planet".

Mr Capriles - whose second surname, Radonski, is inherited from Polish great-grandparents who were killed at Treblinka concentration camp - last month united a traditionally disjointed Venezuelan opposition by winning primary elections with nearly 64 per cent of the vote.

He refuses, however, to be drawn by the smear campaign against him. "The President should be leading by example," Mr Capriles says in an interview with the JC. "Power shouldn't be abused for carrying out personal attacks. It's a temporary gift to serve the people.

"Venezuela is characterised by its open attitude to all immigrants. When my family arrived here, they were welcomed without problem and allowed to establish themselves. That shouldn't change."

While populist Mr Chávez - whose battle with cancer is diminishing his chances of standing against Mr Capriles in October's presidential election - has often stated he is not antisemitic, his open hatred of the US and his "anti-imperialist" revolution have seen him develop close ties with Iran and break off relations with Israel.

Jewish groups in Venezuela complain of an exodus, claiming that the number of Jews has halved in the past ten years to around 9,000.

"It's part of a wider problem that affects all Venezuelans," says Mr Capriles, who, despite being a practising Catholic, is proud of his Jewish roots. "The cause is the increasing level of insecurity we live with." Caracas is one of the most dangerous cities in Latin America and high crime rates are considered one of the Chávez revolution's biggest failures.

The government has been criticised by Jewish groups in Venezuela and the US for having put out antisemitic messages through state media. Most recently, an article published on the Venezuelan National Radio website begins by targeting Mr Capriles's Jewish ancestry before accusing him of fascism and Zionism, which the author claims is an "imperialist ideology of terror".

"There's a lot of desperation," says Mr Capriles, 39, whose Jewish paternal grandparents were from the 200-year-old Sephardic community in Curaçao. "People will look for anything to discredit me, but we're here to work for the Venezuelan people. I'm dedicated to the future of my country."

Turning to foreign policy, Mr Capriles - wary of making firm commitments at this early stage of his campaign - stops short of explicitly denouncing Venezuela's snug rapport with Tehran. However, the umbrella group the Venezuelan Confederation of Isrealite Asscoiations, said that Mr Capriles told them he would seek to re-establish ties with Israel.

"We want a politics of respect with all countries," he says. "And we desire a win-win relationship with both Israel and Iran. I propose a free, tolerant Venezuela that promotes peace and encourages human rights."

Polls suggest that, come October, Mr Capriles may well be given the opportunity to build his vision. The one certainty is that Mr Chávez is in for a tough fight.