Poland braced yesterday for an election forced by the death in an air crash of conservative president Lech Kaczynski, as polls showed a tight race between his twin brother and the governing liberals' candidate.

Ex-prime minister Jaroslaw Kaczynski and liberal rival Bronislaw Komorowski pushed to the wire until a campaign blackout came into force last Friday at midnight.

A flurry of final surveys suggested today's contest could be closer than previously forecast, with floating voters holding the key.

A range of polls gave Komorowski 45-54 per cent, and Kaczynski 42-45 per cent.

Liberals remember only too well how Lech Kaczynski came from behind to beat their candidate Donald Tusk - now prime minister - in the 2005 presidential election.

Lech Kaczynski perished on April 10 when his jet crashed in Smolensk, western Russia as it landed for a World War II commemoration. A total of 96 people died, among them his wife, senior politicians and the Polish military's top brass.

Under the constitution, speaker of parliament Komorowski be-came acting president after the crash.

Still reeling, Poland was battered in May and June by the worst floods in decades which killed 24 and forced thousands from their homes.

Both disasters overshadowed the campaign.

"This election began with a tragedy. I hope it will end with a great success for Poland," Jaroslaw Kaczynski said at a final rally last Friday.

The result is crucial because it could end - or extend - a logjam caused by wrangling between conservatives and liberals.

Jaroslaw Kaczynski, head of the twins' Law and Justice party, was premier in 2006-2007 but lost a general election to the liberal Civic Platform.Law and Justice could still count on Lech Kaczynski, who used his presidential veto powers 18 times to block government legislation.

He had been been expected to stand in an autumn election but, with his popularity having slumped, was not expected to win a second term. With an eye on core conservative voters - who tend to be older, small-town or rural residents, in contrast with younger, urban liberals - the twins battled to hold up welfare reforms and a new privatisation drive.