Poll set to be a referendum on ruling Kaczynski twins.
In his campaign manifesto, Tusk also said one of his top 10 priorities would be withdrawing Poland’s 900 troops from Iraq, a pledge that could prove popular.
But Jaroslaw Kaczynski’s conservative message goes down well in rural Poland, although in the country’s larger cities many people worry that he is dividing society.
One PiS supporter, Tomasz Zbrug, told Al Jazeera after weekly mass: “Finally, Poland has something to say to the rest of the European Union.
He told Al Jazeera: “They don’t have the capability to have the rule of government, to rule Poland. Poland needs freedom.
The PO, if successful at the polls, could rule with the Polish Peasant’s party (PSL), with which it already runs several local authorities.
The liberals may also be forced to turn to the Left and Democrats (LiD), an alliance steered by ex-communists, despite the reticence of some in PO’s conservative wing.
Kaczynski’s former allies from the far-right League of Polish Families (LPR) and the populist Self-Defence (Samoobrona) movement are expected to lose their seats.
PiS could try to work with the conservative wing of PO, but analysts say the bitterness of the past two years makes that unlikely.
Lech Kaczynski, the president, will still be in power whatever Sunday’s result, since his five-year presidential term runs until 2010.
|Poland elections facts|
To win seats, political parties must gain at least five per cent of the nationwide popular vote.
Seats are distributed according to the percentage of the vote a party wins, but bigger parties or groups are given a higher proportion.
Senators are chosen by constituency according to a first-past-the-post electoral system, normally benefiting bigger parties.
Parliament must convene within 30 days of the election. The president must name a candidate for prime minister within 14 days of that.