By Jussi Rosendahl
HELSINKI (Reuters) - Finland's anti-euro True Finns party is expected to make big gains in Sunday's parliamentary election, threatening the pro-European government and raising the risk of disruption to an EU bailout of Portugal.
Finland's parliament, unlike others in the euro zone, has the right to vote on EU requests for bailout funds, meaning it could hold up plans to shore up Portugal and bring stability to debt markets.
An opinion poll on Thursday showed the National Coalition -- the second largest party in Finland's governing coalition and an EU supporter -- with a narrow lead at 21 percent of voters.
That would not be enough to secure a majority in parliament, and analysts expect it to seek a multi-party coalition. Some say it could even invite in the True Finns, if the party secures enough votes.
"Whether the True Finns will really (emerge) as the champions of the elections is still uncertain. But I think we will clearly get a more nationalistic, more conservative, less European-oriented government in Finland," ING senior economist Carsten Brzeski told Reuters.
Finland's three other main parties -- Prime Minister Mari Kiviniemi's Centre party, the True Finns and the opposition Social Democrats -- each command the support of between 15 and 19 percent of voters, according to the poll.
Polling stations close at 1700 GMT (6 p.m. British time). Finnish television will broadcast exit poll results shortly afterwards. Official results are due later on Sunday.
The government is expected to be formed mid- to late May.
FEARS PLAYED DOWN
National Coalition minister Jan Vapaavuori on Friday played down fears of an anti-euro government.
The True Finns, he said, would probably be asked to tone down their rhetoric as a condition of joining the coalition.
The Social Democrats, who are critical of the bailout but supportive of the EU, would be easier to get on board, he said.
"I'm sure that Finland will be in line with other European countries in the next government," he told Reuters.
The True Finns have said they have no intention of backing down from their opposition to the bailout. But analysts said the party and its charismatic leader, Timo Soini, would probably compromise if needed.
"It would be strange for a party to grow so much but not want to use that power and enter government," said Kimmo Gronlund, research director at Abo University.
Support for the True Finns has nearly quadrupled since the 2007 election, partly fuelled by anxiety over unemployment and pension cutbacks. The True Finns party leans to the left on social welfare issues.
"Pensioners have been treated very badly. The allowances have come down, and I'm expecting they will be lowered more," said pensioner Liisa Valkama, as she waited to vote.
Finland's rebound from the global financial crisis has done little to boost the number of jobs. Even its flagship company, Nokia, is struggling to compete with Apple Inc and Asian handset makers, and is expected to cut jobs.
"They have strict opinions about everything," one young woman, who gave her name as Eevi, said of the True Finns. "Finnish people have always been very open, I wonder why we are now pulling off, closing up again?"
(Writing by Ritsuko Ando, Editing by Janet Lawrence)