Poles voted Sunday for a new head of state, two months after president Lech Kaczynski perished in an air crash, but his twin brother trailed the ruling liberals' candidate in an audacious power bid. Opinion polls have put parliamentary speaker Bronislaw Komorowski, 58, of the market-friendly Civic Platform ahead of ex-premier Jaroslaw Kaczynski, 61, leader of the eurosceptic conservative Law and Justice party. Poland has been reeling since the April 10 accident in western Russia that killed Lech Kaczynski and 95 others, including his wife Maria and top political and military figures. They had been heading to a memorial ceremony for thousands of Polish officers killed by the Soviets during World War II. The ballot is crucial for the conservatives who, after losing power in a 2007 parliamentary election, counted on Kaczynski's presidential veto to hamper the liberal government's policies. On the other hand, victory for Komorowski -- a close ally of Prime Minister Donald Tusk -- would boost the Civic Platform before parliamentary elections due late next year. 'Either we'll remain locked in bitter conflict, or we'll move on,' Tusk said as he voted in his Baltic hometown, Sopot. In Warsaw, a grinning Komorowski held his vote in the slit of the ballot box for a minute as photographers shouted for him to turn their way. Jaroslaw Kaczynski voted in Warsaw alongside his late brother's daughter. 'I hope turnout is going to be high,' he told reporters. Elections since the 1989 fall of Poland's communist regime have often failed to draw a majority of voters. After seven hours of voting, turnout edged to 24 percent. Polls close at 8:00 pm (1800 GMT). On top of the April 10 crash, the campaign was overshadowed by floods that killed 24 people and drove thousands from their homes. The candidates have appealed to the 38 million Poles for national unity. 'It's our duty to vote, even if our mind is on other things,' said farmer Henryk Boruch in Wilkow, a flood-hit community south of Warsaw. In the capital city, Grazyna Rykowa, 50, said she had voted for Komorowski. 'I chose Bronislaw Komorowski because of his experience in parliament and because Mr. Kaczynski did not pass the test when he served as prime minister -- he already had his chance,' she told selfnews. Komorowski could garner 41 to 51 percent of the vote, and Kaczynski, 29 to 35 percent, surveys show. The other eight candidates lag far behind. If no one tops 50 percent, the two frontrunners face a run-off on July 4, with opinion polls giving Komorowski a comfortable win. Under the constitution, parliamentary speaker Komorowski became acting president after the plane crash. Even before it, he was preparing to challenge Lech Kaczynski's bid for a second five-year term in an election originally scheduled for later this year, and was tipped to win. 'He's been good as acting president. I voted for Lech Kaczynski before, but was disappointed fast,' said ex-policemen Robert Pedzich, 46, referring to Lech Kaczynski's 2005 election victory over Tusk. Despite shared roots in communist-era opposition movement Solidarity, Civic Platform and Law and Justice are bitter rivals. 'They're similar as candidates really, both of them with roots in the anti- communist opposition, but I voted for Jaroslaw Kaczynski -- he's more inclined to social welfare,' said 25-year-old Michal Luczak. Outside Warsaw's presidential palace, in front of a portrait of the late Kaczynski couple adorned with flowers, candles and a plain wooden cross, teacher Maira Szczepanska, 64, said she was voting for the twin. 'Lech Kaczynski was a patriot, he remembered our history, he stood up for Poland. He respected the wealthy but never forgot about the poorest of the poor and his brother stands for the same thing,' she said. Jaroslaw Kaczynski was premier in 2006-2007. The period was marked by regular clashes between the twins and fellow EU leaders -- Poland joined the bloc in 2004 -- plus mudslinging at home. The pro-EU Civic Platform trounced Law and Justice in the 2007 general election. 