Pro-business moderate Donald Tusk finished first in Poland's presidential election Sunday, but fell short of a majority, forcing a run-off against second-placed conservative candidate Lech Kaczynski, early exit polls showed.

Two exit polls gave Tusk, of the Civic Reform party, around 38 percent of the vote, compared to 32 to 33 percent of Kaczynski's Law and Justice party.

Far-left populist Andrzej Lepper got 13 percent and Social Democrat Marek Borowski 9 to 10 per cent.

The second round of voting for a successor to outgoing leftist President Aleksander Kwasniewski will take place on October 23.

A victory by either Tusk or Kaczynski will cement a swing to the right in the European Union newcomer after their parties, heirs to the pro-democracy Solidarity movement, trounced the ruling left in a parliamentary poll last month.

Civic Platform and Law and Justice have started negotiations on forming a coalition in parliament, talks which will be influenced by the final results of the presidential poll.

Both men favour free market economics, but Kaczynski puts more stress on Catholic and family values. He wants a more conservative republic.

Meanwhile Tusk has spoken of the "great opportunity" offered by Poland's entry to the European Union last year.

The current president, former communist Aleksander Kwasniewski, is unable to stand again, having served the maximum two five-year terms permitted.

Under Poland's constitution, the president has less power than the country's prime minister, but retains a significant say in foreign policy.

Tusk has said if he is elected, he would like to give increased weight to the president.