Finland's 4.3m voters go to the polls on Sunday with Prime Minister Matti Vanhanen's centre-left government hoping for a second four-year term.
Political campaigning has generally been low-key
A recent Gallup poll indicates that 43% of voters back a return to power of the Centre Party, Social Democrats and Swedish People's Party.
Less than a quarter of voters say they prefer a coalition between the Centre Party and opposition Conservatives.
It is exactly 100 years since Finland held its first ever election.
The Centre Party has retained a narrow lead over its two major rivals in the pre-election polls, but it could switch to a centre-right alliance with the Conservative National Coalition, if the latter puts in a strong election performance.
"If that happens, it really could be an interesting election night and anything could happen," said Tom Moring, professor in communication and journalism at the University of Helsinki.
Another Gallup poll has found support for the Social Democrats and Conservatives to be running nearly neck-and-neck.
The largest party in the polls traditionally forms a parliamentary majority and names the prime minister.
Political analyst Tuomo Martikainen told Finnish YLE TV that recent polls had shown higher levels of electoral support for the conservative parties. "A conservative surprise may be brewing," he said.
All Finland's big parties have governed together in broad coalitions in recent history.
A total of 1.04m voters, or 29% of the electorate, have already cast their ballots in a week of advance voting.
Analysts say this is a higher figure than in the past, and there is some evidence that this could favour more conservative parties.
Despite attempts by the major parties to increase popular interest, Professor Moring said the election campaign has been one of the most low-key in Finland's recent history.
Prime Minister Vanhanen, 51, has seen his popularity grow
But the political debate has gained momentum in recent days, with the focus turning to healthcare, care for the elderly and help for students.
Finland has one of Europe's most rapidly ageing populations and there is widespread concern about a future shortage of caregivers for the elderly.
The personality of Prime Minister Vanhanen, who heads the Centre Party, could also be a factor in swaying voters.
"His personal popularity is high," Professor Moring said. "He is no Tony Blair but he appears to have convinced people by a kind of honesty."
The publication of a controversial book by Mr Vanhanen's former girlfriend may also have an impact. The book, which describes their past relationship, was released as campaigning began last month and immediately became a bestseller.
"Vanhanen has been seen as a rather dry, bureaucratic prime minister who is teetotal," said Jan Sundberg, a professor of political science at the University of Helsinki.
"I would say his popularity has improved directly because of it [the book]."