Voter turnout was expected to be higher as politicians have urged people to exercise their right to vote as a way of expressing their rejection of Behring Breivik's theories.

The anti-immigration extremist killed 77 people in twin attacks on July 22nd, first setting off a bomb at the Labour government offices and then carrying out a shooting massacre at a Labour youth wing summer camp on an island near Oslo.

In his manifesto published on the internet just before the attacks, Behring Breivik professed his hatred for Western-style democracy, saying it had spawned the multicultural society he loathed.

"You really need a good excuse not to vote this year," said 30-year-old Haakon Holm after he cast his ballot at Oslo's city hall.

"More than ever we need to reaffirm our commitment to democracy and disown those who try to destroy the system by using violence," he told AFP.

Some 530,000 people had already cast their ballots in advance voting, compared to 374,000 in 2007, an indication that turnout could be higher than last time when 61.7 percent of the electorate voted.

Following the attacks, Norway's politicians urged the public to turn out en masse on election day.

In the hours after the massacre Labour Prime Minister Jens Stoltenberg vowed there would be "more democracy, more transparency" in Norway, a message overwhelmingly acclaimed by the public, according to opinion polls.

"Never have municipal and regional elections been as symbolic as this year," Norway's paper of reference, Aftenposten, wrote in an editorial on Monday.

"The important thing is not for whom you vote, but that you vote," it added.

The Labour party received a wave of sympathy immediately after the massacre and saw Stoltenberg's popularity rise.

The party is likely to be spared the heavy defeat it was headed for prior to the attacks, though the "July 22 effect" is hard to quantify, according to observers.

"Initially I was going to vote for the Labour party in reaction to the attacks. But in the end I decided that the best thing I could do for democracy was to vote in line with my beliefs, not my emotions," said Anders Holm, 26, who inked his support for the small Liberal party.

Public opinion polls suggest the Labour Party and Conservatives will be the big winners of the elections, with the right-wing retaining power in most big cities.

The Progress Party, the right-wing anti-immigration grouping of which Behring Breivik was once a member, is expected to register a mediocre score, according to experts, though its woes are not directly linked to its former ties with Behring Breivik.

The party has vehemently distanced itself from him.