Opinion polls show the Law and Justice Party (PiS) of prime minister Jaroslaw Kaczynski, one half of the ruling double act, 4%-12% behind opposition leader Donald Tusk's Civic Platform.

"Kaczynski promised to sort out Poland and make it a better place to live, but he hasn't, " said Czarniawska, a Warsaw office worker. "He talks about stopping corruption and helping the poor but all we've had is chaos and arguments."

The Kaczynskis became Poland's most powerful men in 2005, when Jaroslaw guided PiS into government and Lech secured the presidency on a pledge to crush corruption, redistribute wealth and smash a network of ex-communists that the twins claimed ran the country.

Two years on, the twins claim to be fulfilling those promises, as well as helping the economy grow at 6% a year and winning international respect for Poland through robust dealings with the EU and Warsaw's old foes, Russia and Germany. Nonsense, say critics who call the Kaczynskis megalomaniacs who have wasted time settling scores rather than energising Poland with reforms that would persuade its people to stop emigrating.

"Two million Poles chose a liberal economy in the two years that you have been in power.

Unfortunately, it was in the UK, Ireland, Spain and the Netherlands, " Tusk said in a feisty preelection debate.

Tusk's verbal battering of a flustered and poorly prepared Kaczynski sparked a surge in ratings for Civic Platform, which favours liberal economic reforms and rejects the twins' aggressive foreign policy and ultraCatholic moral conservatism.

But if Tusk does oust the prime ministerial twin, he will swiftly find himself locked in battle with the presidential one. A Tusk government would struggle to gain the 60% majority needed to override the presidential veto on new legislation, and Lech's term does not end until 2010.