Updates with exit poll results, quotes from Tusk, Kaczynski (first version posted at 00:54)
Prime Minister Donald Tusk's Civic Platform looked set to become Poland's first party to win re-election since the fall of communism, as exit polls after Sunday's parliamentary elections showed it leading with nearly 40 per cent, dpa reported.
"I want to thank all Poles who proved that ... all those four years had a deeper meaning for Poland, for all Poles and for Civic Platform," Tusk said at a rally after polling stations closed. "Tomorrow will come the first (coalition) talks, but we will still wait for official results."
Poland holds the rotating presidency of the European Union, and Tusk has centred his campaign on securing money from Brussels to modernize infrastructure. He is regarded as pro-EU and eager to build stronger relations with Germany and Russia.
Foreign Minister Radoslaw Sikorski said the election was a sign of support for the party's work with the EU and modernization of Poland.
The opposition Law and Justice party, headed by Jaroslaw Kaczynski, was second with about 30 per cent support.
The party would keep its stance that Poland needs "far-reaching changes," Kaczynski said at a rally.
"Our task in the next four years will be to convince the next million of Poles ... that changes are necessary, and that a new shape of Poland is needed," Kaczynski said.
Kaczynski has argued that Warsaw should take a tougher stance in relations with Berlin and Moscow. He came under fire recently for saying that German Chancellor Angela Merkel wanted polish "subordination."
Palikot's Movement, formed last year by former lawmaker Janusz Palikot, came in third with about 10 per cent in the exit polls. The party surprised analysts when it gained support with its anti-clerical platform, which supported legalizing marijuana and civil unions for homosexuals.
The agrarian Polish People's Party was around 8 per cent, while the Democratic Left Alliance was at nearly 8 per cent support.
Bomb hoaxes delayed voting earlier Sunday at two polling stations.
A 70-year-old man was arrested in Lublin, in south-eastern Poland, after he allegedly placed a suspicious package near the entrance of a polling station.
Voting at a station in Gorzow Wielkopolski, in western Poland, was also delayed by two-and-a-half hours after police were notified of a suspicious package.
Both packages turned out to be fake bombs, police said.
Nearly 31 million registered voters were eligible to cast their ballots to select 560 new parliamentarians, following an election campaign dominated by debates on the financial crisis and health care reform.
Voter turnout was nearly 40 per cent at three hours before the polls closed, the National Election Commission said.
The elections were being observed by delegations from Egypt, Tunisia and Libya, who said they hoped to introduce similar procedures following the democratic reforms in their countries.
Final results expected on Tuesday.