WARSAW - Poland`s liberals held all the reins of power Monday after their candidate Bronislaw Komorowski foiled conservative Jaroslaw Kaczynski`s audacious bid to replace his late twin in a presidential election.

Komorowski`s victory means the Civic Platform controls both the government and the presidency, after a long power struggle.

Ex-prime minister Kaczynski, chief of the opposition Law and Justice party, conceded defeat late Sunday as exit polls showed he had failed in his quest to succeed his identical twin, Lech, who died in a plane crash in April.

With 95.1 percent of votes counted, Komorowski had 52.63 percent and Kaczynski 47.37 percent. Final results were due later Monday.

The race between Komorowski, 58, and Kaczynski, 61, marked the latest round in a bitter battle between their camps, once allies in the communist-era Solidarity opposition.

Komorowski vowed, however, to end the bad blood in the nation of 38 million.

"Divisions are an inseparable part of democracy," Komorowski said late Sunday. "But we have work to do to ensure these divisions don`t prevent cooperation."

Komorowski -- who as speaker of parliament became acting president after the crash -- is a close ally of liberal Prime Minister Donald Tusk.

Underdog Lech Kaczynski beat Tusk in a 2005 presidential race marked by mudslinging beyond that often seen in Polish politics.

Jaroslaw was his brother`s premier in 2006-2007 but lost a general election to Civic Platform after his controversial coalition with populists and the far right unravelled.

Thereafter, Law and Justice counted on Lech, who used presidential veto powers 18 times to block the liberals` laws.

Lech was expected to seek a second five-year term in a vote later this year but had trailed Komorowski in polls.

Jaroslaw struggled to shake off his confrontational image and failed to build on the outpouring of sympathy after his twin`s death.

Lech, his wife Maria and 94 other Poles died when the presidential jet crashed on April 10 in Russia as their delegation landed for a World War II commemoration.

With an eye on core conservatives -- older, small-town or rural dwellers, in contrast with younger, urban liberals -- the twins battled welfare and health service reforms and a new privatisation drive.

The liberals underscored that Poland was alone in the 27-nation European Union in posting economic growth last year but said gaping holes in state coffers needed plugging.

Holding all the levers now will test the Tusk government.

"Of course there will be no excuse not to push through reforms," said Danske Bank economist Lars Christensen.

Poland holds municipal polls later this year and a general election in 2011.

With belt-tightening a potential vote-loser, political scientist Stanislaw Mocek said Civic Platform was in a bind.

"They`re between the hammer and the anvil, between reform expectations and the looming elections. There won`t be any reforms this year," he claimed.

Witold Orlowski, an economist at PriceWaterhouseCoopers, said he expected a mixed approach.

"Short of a major crisis, the government will be very prudent in order not to damage its election chances while being sufficiently rigorous to avoid the risk of a financial crisis," he said.

The Polish tabloid Fakt put it bluntly: "You have all the power now. Show us what you`ve got. You have a year."

Jaroslaw Kaczynski is already looking to upset the liberals` drive.

"This was a great rehearsal," he told supporters.

"We have to continue changing Poland: there are elections ahead of us, local and parliamentary. We have to continue to be mobilised, we must win," he said.

Sunday`s vote was watched closely elsewhere in the EU, which ex-communist Poland joined in 2004. The Kaczynskis often clashed with other leaders, notably of Germany.

German Foreign Minister Guido Westerwelle welcomed Komorowski`s election as a "strong pro-European signal".

BDST: 17:01 HRS, July 5, 2010