Yet the clashing philosophies of the winning partners - the Law and Justice party and the Civic Platform party - suggest a tense struggle during difficult coalition talks over the next few months. Law and Justice, the senior partner, is proudly nationalist, Catholic and socially conservative. Civic Platform is pro-European and economically liberal. "This is going to be a difficult time," said Lena Kolarska-Bobinska, director of Warsaw's Institute of Public Affairs. "The question is whether these parties will block each other." Both parties spring from the anti-communist Solidarity movement. The partners will have to move quickly to tackle the twin issues of the election - corruption and unemployment of nearly 18 percent - in a country where no government has won re-election since the fall of communism 16 years ago. Jaroslaw Kaczynski, leader of the conservative Law and Justice party and the likely new prime minister, said Monday that he would fight the country's endemic corruption, which under the previous government of the Democratic Left Alliance led to widespread public hatred of the party of former Communists and caused its rout in the election Sunday. "We must rebuild many things in Poland," Kaczynski said. "We must restore trust in the state, something which has been highly compromised in recent years." The anticorruption drive is one issue that the new coalition partners should be able to unite behind, but their alliance will be more sorely tested on economic policy. The unexpected ascendancy of Law and Justice - after the liberal Civic Platform was well ahead in opinion polls until last week - means the pace of economic change in Poland will be slower than Civic Platform promised. Law and Justice drew support from the demise of the Democratic Left Alliance after its candidate for president withdrew amid corruption allegations, and Kaczynski won over left-leaning voters with bitter attacks on his would-be partners' program for a flat 15 percent rate for personal, corporate and consumption taxes. On Monday, Kaczynski promised "lower taxes and pro-investment policies to stimulate the economy." But he ruled out the flat tax, and the divergence in approach to the economy appeared already to be causing friction between the prospective partners. Law and Justice, which favors a far more interventionist approach to the economy than Civic Platform, says it will seek to scale back the independence of the central bank because it believes interest rates are too high, and wants to slow the privatization of state assets. Hanna Gronkiewicz-Waltz, a former central bank governor and one of Civic Platform's candidates for finance minister, said Law and Justice's victory "is worrying news for investors," according to Bloomberg. The news agency quoted her as telling Polish public radio: "This will mean a slower decline in unemployment and less foreign investment. This will make our fight for the flat tax and fast euro-adoption pretty hopeless." Mateusz Szczurek, an economist at ING Bank in Warsaw, said he thought the two parties were still capable together of pushing through significant economic change despite their differences. "I can still see very positive developments being done by the new government," he said, adding that Polish zloty had initially weakened on financial markets Monday after Civic Platform's weaker-than-expected showing but had later recovered. "I believe that change is going to happen," he said. Krzysztof Bobinski of the Unia and Polska Foundation said there could be tensions on European policy because Law and Justice was more skeptical about Poland's role in the European Union. "This will make Poland's Europe policy more difficult," he said. There could be further divergences on attitudes toward Germany and Russia, with Kaczynski, and his brother Lech Kaczynski, who is standing for president, urging a more muscular, confrontational approach to Poland's neighbors. With about 90 percent of votes counted Monday, Law and Justice commanded about 27 percent of the vote, and Civic Platform had 24 percent. This translated into 285 seats for the alliance in the 460-seat Parliament. The governing Democratic Left Alliance had around 11 percent of the vote, a precipitous decline from its 41 percent share in the 2001 election. The anti-European Self-Defense was set to become the third-largest party, with 12 percent of votes. Turnout was 39.25 percent, the lowest for a parliamentary election in post-communist Poland. Talks on forming the new government were expected to begin this week, but were unlikely to be completed until after the presidential elections next month, analysts said. The victory for Law and Justice in the parliamentary elections was potentially a boost for Lech Kaczynski in the presidential election on Oct. 9. Jaroslaw Kaczynski has said he will not stand for prime minister if his brother wins the presidency. But Kolarsko-Bobinska of the Institute of Public Affairs said Lech would not win the presidency and that Donald Tusk, the candidate of Civic Platform who has been far ahead in opinion polls, remained the favorite to win. People on the streets of Warsaw on Monday voiced the optimism they had toward Poland's likely new government, but also the impatience they had for a better economy and a cleaner society. "I think they will be good. Maybe," said Agnieszka Pulkowska, who works in a bookstore. Lodomir Bojczuk, 22, a sociology student, said the new government had to sort out the country's hospitals and schools. "I don't believe they will do what they say," he said. Some people said they had not voted because there were no good politicians, others would not say which party they had voted for, but most Poles appeared to want to reserve their judgment. "We will have to see what they do," said Mary Okolska, who was handing out leaflets on a street corner near the university. "We need more jobs and higher incomes for the jobs people do."