(updates with outcome from Social Democrat meeting)
By Alan Crosby
PRAGUE, Nov 23 (Reuters) - Czech rightist Prime Minister Mirek Topolanek and the leftist Social Democrats clashed again on Thursday over the timing of early elections in talks to end a five-month parliamentary stalemate.
Centre-right and leftist parties have been locked in a bitter battle since a parliamentary election in June left each side with 100 seats in the lower house of parliament.
Topolanek and his Civic Democrats agreed on Thursday with the centrist Christian Democrats and the Green Party that the best way to break the deadlock was to form a four-party coalition government, including the Social Democrats, that would rule until an early election in the spring of 2008.
But the proposal was given a cold shoulder by the Social Democrats, who came second in June's election behind Topolanek's party.
"The offer which we received today returns us back to the phase of negotiations which have ended in failure in the past. I think it would be good to return to the offer of a government for three years," Social Democrat vice-chairman Bohuslav Sobotka told journalists.
Social Democrat leader Jiri Paroubek added that his party would say on Monday whether it would accept the proposal, or possibly make a counter proposal.
Topolanek was appointed prime minister by President Vaclav Klaus immediately after the June vote, and subsequently formed a minority government that failed in its first confidence vote.
Klaus picked Topolanek again to try to form a government after his party dominated mid-October senate and municipal elections.
The pressure is mounting on the prime minister to reach a deal with Paroubek.
If the second attempt to form a government fails, the house speaker will choose a new candidate to form a government.
"We are in a different situation than after the election, I think we are looking at those things differently than in July and August ... every party has a willingness for compromise," Topolanek said in explaining why he feels his proposal can work.
The deadlock has yet to hit the booming economy, but it has stopped it from having the stable, strong government needed to implement spending reforms to prepare for the adoption of the euro currency after 2010.
Analysts said it was likely a deal could be struck if the sides could agree on the timing of early elections, although the Social Democrats prefer a coalition with as few parties as possible so they can have greater influence on policy.
If Topolanek fails twice, Paroubek is likely to get the third chance. If three governments fail to win a confidence vote, Klaus may call elections immediately.
The Social Democrats and Christian Democrats want to avoid this since they have slid in opinion polls since the vote and analysts say this could prompt a Christian Democrat deputy to cross the floor and vote for a leftist government. ((Reporting by Jan Korselt and Alan Crosby; prague.newsroom@reuters.com; Reuters Messaging: alan.crosby.reuters.com@reuters.net; +420 224 190 477; editing by Alison Williams))
Keywords: CZECH POLITICS