Wellington - New Zealand's election on November 8 pits Helen Clark, a parliamentary veteran and one of the astutest politicians the country has seen, against John Key, a political learner who would be the most inexperienced prime minister elected in more than a century if he wins.

Clark, 58, has been a Labour member of parliament since 1981 and, not satisfied with making history as the only leader of the party to win three consecutive elections, is bent on winning a fourth for another three years in power.

Key, 47, did not enter parliament - where he is the richest member, having made a fortune as a foreign currency dealer overseas - until 2002, and he has led the main opposition conservative National Party less than two years.

Politics has ruled Clark's life to the extent that she admitted getting married only because it seemed necessary to get elected at the time. And she is childless by choice because she never intended to let anything interfere with her political career.

Single-minded and tough, like former British prime minister Margaret Thatcher, she has been dubbed "the toughest man in the cabinet."

But the resemblance ends there. A lifetime socialist, she has called her rich conservative opponents "loathsome people."

Key's inexperience has shown up in combat with Clark in parliament, and although his party is well ahead in opinion polls - probably reflecting fair-minded Kiwi voters' inclination that after nine years it is time "to let the other lot have a go" - he can take nothing for granted.

He will be tested on the hustings and particularly in televised debates with Clark. He made the mistake recently of likening himself to US presidential candidate Barack Obama in an interview with the Financial Times of London.

It did not matter that he was trying to say he was not "institutionalized" in Wellington as Obama said he is not in Washington - Clark was scathing.

"For Mr Key, a rather wooden speaker at the best of times, to compare himself to one of the most gifted orators of our time is simply preposterous," she said.

Announcing the election date, Clark was at pains to paint it as a traditional clash between socialist and conservative parties.

Despite his wealth, Key was not born with a silver spoon in his mouth. He was brought up in a state house by his mother after his alcoholic father died when he was 6 and has said New Zealand would always have a social welfare system because a society is measured by how it looks after its most vulnerable.

"Once, I was one of them," he said. "I will never turn my back on that."

His statement did not stop Clark's deputy, Michael Cullen, from calling him "a rich prick," and Clark insisted that Key's public statements moving the National Party into the centre are merely a vote-wooing front to hide a secret right-wing agenda.

She said that agenda includes selling state assets, borrowing heavily to fund tax cuts favouring the wealthy, investing in private schools, weakening workers rights and making people pay more to go to the doctor.

Key has adopted a surprising number of Labour's popular policies, including some that he or other members of his party had previously criticized.

Clark dismissed the move as National "flip-flops and evasiveness" and said, "Any convergence to our policies lacks sincerity and credibility - they cannot be trusted."

The irony of what promises to be a presidential-style clash between the pair is that under New Zealand's proportional representation system of voting, the next government is likely to be decided by how minor parties fare.

The system was designed to ensure a broader representation in parliament, and no single party has received more than
41 per cent of the total vote since then.

The result has often been lengthy post-election negotiations to produce a coalition government, and although the National Party is well ahead in opinion polls so far, the gap is narrowing. (dpa)