The leader of the Social Democrats party which narrowly won the Czech general election has been asked to resign by his party, further complicating already difficult efforts to form a new coalition government.  

The centre-left party's leadership body voted 20-13 for chairman and candidate for prime minister Bohuslav Sobotka to quit after the party won only 20.5% of the vote. 

Despite the unexpectedly weak showing at the ballot box, Mr Sobotka vowed to fight on.

The party's vote is not binding and Mr Sobotka said he will not resign, though his fate remains unclear. 

Potential coalition partners expressed shock at the tilt against the party's leader by its deputy chairman and rival of Mr Sobotka, Michal Hasek. 

The vote gives Mr Hasek the initiative as he will lead talks to form a new government with two centrist parties.

After the fall of communism in the 1989 "Velvet Revolution", Czechs have grown disillusioned with established parties which have been stained by corruption scandals.

A wave of voter anger over sleaze and cuts has propelled new protest parties into parliament after the poll.

Centre-right parties that ruled the EU and NATO member country of 10.5 million people until their cabinet collapsed amid corruption and illegal spying allegations in June suffered a crushing defeat in the vote.

A new anti-sleaze party, ANO, came second on almost 19% after a spectacular late surge. 

The Communists came third with almost 15% of the vote. 

The Social Democrats want to start talks with the centrist ANO, the anti-corruption movement started two years ago by mercurial food and agricultural tycoon Andrej Babis. 

Languishing in opinion polls until late in the election campaign, its second place makes it the big winner in the election.

The Social Democrats also want to negotiate with the centrist Christian Democrats to form a three-party coalition.

The two parties which previously held power until June - the Civic Democrats and Top 09 - won just 7.5% and 11.5% respectively.

The election result leaves the prospect of protracted political haggling and of another weak and unstable government just as the Czech economy emerges from a lengthy recession.

The poll dashes Mr Sobotka's hopes of forming a minority government with the parliamentary support of the Communists because the two parties cannot muster a majority.

A Social Democrat government would be expected to slap new taxes on banks, utilities and high earners to pay for social programmes and help keep the budget deficit below the EU's prescribed level of 3% of national output.

However ANO leader Mr Babis - who owns more than 200 chemicals and food firms as well as two national newspapers - quickly dampened any hopes that ANO might be ready to help Mr Sobotka.

"I cannot see us supporting the Social Democrats given the programme they have," said Mr Babis.