OSLO (AFP) - Norway's right-wing opposition leads in the polls ahead of Monday's election as voters itch for change despite the oil-rich country emerging largely unscathed from the global economic crisis.

In what is set to be a close race, the four right-wing parties could win a parliamentary majority and be in a position to oust the left-wing government that has been in power since 2005, opinion polls suggest.

Yet Prime Minister Jens Stoltenberg, whose Labour Party leads a coalition with the Socialist Left and Centre Party, can paint a rosy picture of his country's development over the past four years.

Rich in oil and gas and regularly topping the UN's human development index that measures quality of life, Norway has limited the effects of the global economic downturn by dipping into its massive sovereign wealth fund worth 277 billion euros (395 billion dollars).

After a brief recession, the Scandinavian country now boasts the lowest unemployment rate in Europe, at 3.0 percent in August.

"It's not a coincidence. It's because the government stepped up, took vigorous steps and did everything it could to help Norway exit the crisis unharmed," Stoltenberg said.

But despite his government's strong report card he still faces an uphill battle in the election.

Since Norway in 1996 started putting its oil revenues aside in a state pension fund, no government has ever won re-election.

Political observers call it the "oil curse": despite the wealth, Norwegians have consistently punished the sitting government at the voting booths for what they perceive as parsimonious use of their oil dollars.

"When a state has abundant amounts of oil revenues, it's very easy to sow discontent by pointing the finger at the things that aren't working well. It's a kind of 'oil populism'," the political chief editor at Norway's leading daily Aftenposten, Harald Stanghelle, told AFP.

The Progress Party, the biggest opposition party with some 25 percent of voter intentions, have called for sizeable tax cuts and increased public investments, primarily financed by bigger dips into the state pension fund.

"The critical factor is not only how much money we spend but also how we spend it. Investing in infrastructures is not spending money, it's investing in future GDP (gross domestic product)," Progress Party leader Siv Jensen said.

That argument, combined with pledges to curb immigration and halt what it calls the "sneak Islamisation" of Norwegian society, has hit home with voters.

"Norway is the richest country in the world but we still pay the highest taxes: value-added tax is 25 percent, we have staggering taxes on cars and exorbitant income tax," rages Baard, the 45-year-old head of a small business who plans to vote for the Progress Party on Monday.

While the right-wing could be in a position to topple the government, the bloc is nevertheless far from a united group and has yet to agree on a joint platform for a government should it emerge victorious.

With the "hot topics" of EU membership and Norway's military presence in Afghanistan virtually ignored in the run-up to the election, the campaign has focused on who will ally with whom.

The two centre-right parties, the Christian Democrats and the Liberals who together are credited with just over 10 percent of voter sympathies, have ruled out a collaboration with the Progress Party in a coalition that would also comprise the Conservatives.

And Siv Jensen has refused to support a government that does not include her Progress Party.

"I think it's a democratic problem that it's seen to be more important to keep us outside than actually giving us and our voters the influence that we're supposed to have," she said.

The divisions could benefit Conservative Party leader Erna Solberg who, with some 15 percent of voter intentions, could build a bridge between the centre-right and the Progress parties.

An impasse could also benefit Jens Stoltenberg, who could return to power at the head of a minority Labour government.