Attempts to form a new Czech government after this weekend's election suffered a setback on Sunday when the winning centre-left party tried to oust its leader due to an unexpectedly weak showing at the ballot box.
The Social Democrats' leadership body voted by 20 to 13 to call on chairman and candidate for prime minister Bohuslav Sobotka to quit after the party won only 20.5% of the vote.
But Sobotka vowed to fight on, saying his rivals, led by deputy chairman Michal Hasek, would be under the influence of President Milos Zeman, Sobotka's longtime rival and a former Social Democrat prime minister.
"I will not resign because I want to keep defending values I believe in within the (party). Among them is an independent Social Democratic party," Sobotka, 42, said.
A quarter of a century after the fall of Communism in the 1989 "Velvet Revolution", Czechs have grown disillusioned with their political class and used their votes to protest against established parties, including the Social Democrats, that have been stained by corruption scandals.
Sobotka's fate was unclear - the call to resign was not binding - but Hasek, 37, has the initiative as he will now lead the coalition talks with two centrist parties.
Hasek's faction met Zeman late on Saturday, Czech media reported. Zeman has in the past hinted he may prefer Hasek as prime minister after the election.
Zeman angered parties in July when he pushed through a caretaker cabinet made up of his allies, which will continue to rule until a new government is formed.
The Social Democrats want to start talks with the centrist party ANO, an anti-corruption movement started two years ago by food and agricultural tycoon Andrej Babis, 59, that came second in the election. They also want to negotiate with the centrist Christian Democrats to form a three-party coalition.
Centre-right parties that ruled the EU and NATO member country of 10.5 mln until their cabinet collapsed amid corruption and spying allegations in June suffered a crushing defeat in the vote.
Analysts said Hasek's move was motivated by personal ambition and his fight with Sobotka was hurting the party.
Social Democrat leaders said on Sunday said they could agree with ANO on anti-corruption measures, such as laws requiring the publishing of public contracts.
But they will struggle to follow through on plans to raise taxes for high earners and utilities, telecoms companies and banks because of ANO's opposition to tax hikes. Babis is also cooler on adoption of the euro than the pro-European Social Democrats.
Markets have been unfazed by the election but messy coalition talks, an increasingly likely scenario, could unsettle investors. Local markets are closed on Monday for a holiday.
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