It is unlikely that the Finnish vote will upend or even delay the Portuguese package, though it could lead to some nervous moments. Usually, it takes about a month to build a governing coalition in Finland, and that is at times when the political parties are not as far apart as they are now.

This week, the departing prime minister, Mari Kiviniemi, declined to bring the bailout issue before Parliament, saying it was up to the new government. At the same time, Olli Rehn, the European Union’s economic and monetary affairs commissioner, was quoted in the Thursday edition of the Finnish daily Helsingin Sanomat as saying that Finland needed to take a stand on Portuguese aid by May 25 at the latest.

The new government is expected to include the right-of-center National Coalition Party, the left-leaning Social Democratic Party and the True Finns. The parties disagree on issues like the bailout, tax reform and increasing the retirement age.

Mr. Soini (pronounced SOY-knee) has toned down his words in the last few days, though it is unclear how far he will compromise. He is not talking to the news media except to complain about coverage of his party. But during the campaign, Mr. Soini — who is 48 and has been active in politics since he was 17 — repeatedly lashed out at the European Union. (He is fond of calling it “the heart of darkness.”) A true democracy, he has said, is “only possible in individual states.”

He has also sold himself as a man of the people who is attuned to the needs of the poor and working class at a time when the distance between rich and poor is growing and Finland, like many other European countries, is considering austerity measures.

“Soini talks ordinary language with ordinary words,” said Ville Pernaa, the director of the Center for Parliamentary Studies at the University of Turku in Finland. “He told the voters that they were wasting money paying for other people’s debts. Why should they pay for that when we need more doctors in the small towns of Finland?”