A pair of center-right parties that promise tax cuts and clean government appeared well-placed to wrest power from Poland's governing Democratic Left Alliance as voters cast ballots in Sunday's general election.
Some 30 million people in the nation of 38 million were eligible to vote. First partial results were expected Sunday night, but full official results were not expected until Tuesday.
It remained unclear which of the two leading parties - the economically liberal Civic Platform or the socially conservative Law and Justice - would emerge with the upper hand in the European Union's biggest new member country. Recent polls have shown the two parties neck-and-neck; both have said they would form a coalition.
Opinion polls predicted such low support for the governing Democratic Left Alliance that it was not even certain of clearing the 5 percent threshold to enter parliament.
Though the party came to power with 41 percent support in 2001 and saw the country into the European Union last year, its popularity has plummeted amid a string of scandals and its failure to tackle the EU's highest jobless rate, currently at 17.8 percent.
The pro-market Civic Platform has long enjoyed the lead in opinion polls, after campaigning on a platform to reduce state bureaucracy and push for 15 percent flat-rate income tax.
But it has been overtaken in some surveys by Law and Justice, which wanted less drastic tax cuts and the preservation of many welfare-state protections.
One of the last polls before the vote showed Law and Justice with 33 percent support, up five percentage points from five days earlier, and Civic Platform with 28.7 percent, down six points. That suggested Polish voters, like their German counterparts last weekend, may get cold feet at the ballot box about pro-market changes.
The OBOP research center questioned 1,511 adults on Sept. 21-22 for the survey, carried out for state television. It gave a margin of error of plus or minus 3 percentage points.
Those numbers would translate into a comfortable center-right majority in the 460-seat lower house of parliament, or Sejm, and in the 100-seat Senate.
Still, a bitter tone has emerged between the two parties over the past week as they tried to stake out firm positions - in part by attacking the other's program - raising the possibility of a struggle over economic policy.
Law and Justice has said Civic Platform's plans for a single, 15-percent income tax rate would help only the rich, and has run TV spots showing food disappearing from a refrigerator to illustrate their contention that it would hurt low-income families.
Party leader Jaroslaw Kaczynski called Civic Platform's tax plans "a joke."
But Jan Rokita, Civic Platform's candidate to be prime minister, has argued that only pro-market reforms can boost business and generate wealth in the formerly communist country, where the average monthly salary is about 2,500 zlotys (US$775; 640).
The next government will face the task of preparing Poland to join the euro zone, which will mean painful spending cuts to trim its budget deficit. Both leading parties have supported adopting the common European currency, though it is a greater priority for Civic Platform.
The current prime minister, Marek Belka, has fallen out with the governing party, and last month agreed to run as a candidate for a new group, the Democratic Party.
The business community favors a Civic Platform victory, and Poland's currency, the zloty, dropped Wednesday after a poll showed Law and Justice ahead.
If the outcome is very close, the choice of prime minister could be complicated by the fact that Poland also faces presidential elections on Oct. 9, with a likely runoff vote two weeks later.
Law and Justice leader Kaczynski's identical twin brother, Warsaw Mayor Lech Kaczynski, is one of two leading candidates in that race. The other is Civic Platform's Donald Tusk.
Jaroslaw Kaczynski has said that, if his brother wins, he would renounce the premiership in order to spare Poland the confusion of two major leaders who look alike.