The new Czech centre-right government has lost a vote of confidence 30 days after being sworn into office.
Mirek Topolanek's government lasted only a month
Just under a half of the 195 MPs present in the lower house on Tuesday voted in favour of Mirek Topolanek's minority cabinet.
The government now must resign, raising the prospect of early elections.
The Czech Republic has been in a political stalemate since elections in June left parliament split down the middle between left and right.
The drama that has gripped the nation since June's dead-heat parliamentary elections is now becoming something of a political farce, the BBC's Rob Cameron reports from Prague.
The latest instalment came on Tuesday afternoon when Prime Minister Mirek Topolanek went before the lower house to seek a vote of confidence.
As expected he failed. He and his government will have to resign.
President Vaclav Klaus will have to appoint a new prime minister.
He may give Mr Topolanek another opportunity to form a cabinet, but if that fails, the speaker of the lower house, who is from the opposition Social Democrats, will nominate a new prime minister.
With parliament split down the middle between right and left, our correspondent says the only viable option is a grand coalition - but that this is a solution that nobody wants.
So the most likely outcome is a caretaker government to lead the country to early elections, our correspondent says.