A pro-market lawmaker and Warsaw's socially conservative mayor appeared headed for a runoff after neither candidate appeared to have gained the majority of the vote needed for an outright win in Poland's presidential election on Sunday, according to preliminary results and a key exit poll.

With 91.5 percent of the ballots counted, the state electoral commission said 36 percent of voters had backed Donald Tusk, a pro-business candidate committed to stimulating entrepreneurship with low taxes and deregulation, while 33 percent had voted for Warsaw Mayor Lech Kaczynski, a former child actor who hopes to preserve a strong social safety net.

A state television exit poll indicated that Tusk finished with about 38 percent and Kaczynski with 32 percent. Turnout was nearly 50 percent.

If the results hold, the two candidates, both former activists with the anti-communist Solidarity movement, will be forced into a runoff on Oct. 23.

The race in the formerly communist country centered on the Europe-wide issue of just how far to go in sacrificing old welfare-state protections for the goals of fast growth and job creation.

Final results were not expected until Monday, the electoral commission said, but exit polls in Poland have proved in the past to be a reliable indicator of the final tally.

"This is a victory," a smiling Tusk proclaimed. "I'm happy that millions of Poles decided it was worth going to vote, and that it was worth voting for Donald Tusk."

Kaczynski has an identical twin, Jaroslaw, whose Law and Justice party won the parliamentary election. As party chairman, Jaroslaw was expected to become prime minister, but he instead named a little-known party member to hold that post, a move aimed at strengthening his brother's bid for the presidency.

Donald Tusk backs low taxes, deregulation. Lech Kaczynski is mayor of Warsaw.