Polish Prime Minister Jaroslaw Kaczynski has sacked his deputy, raising the prospect of an early general election.
The prime minister said he was not afraid of an early election
Mr Kaczynski sacked Andrzej Lepper, who leads a junior coalition party, after his name was linked to a major corruption case involving bribes.
Hours later, Mr Lepper withdrew his Self Defence party from government.
Mr Kaczynski told a news conference that an early election might be the only solution to the political crisis.
"The aggression of the opposition makes it impossible to have a minority government", Mr Kaczynski said.
An election could be held in the autumn, two years ahead of schedule.
Self Defence has 46 deputies in the 460-seat Sejm, the lower house of the parliament. Without them, the government can count on the support of only 203 deputies - far short of the 231 needed for a majority.
Soon after the prime minister spoke, the second biggest opposition party, the Democratic Left Alliance (SLD), said it would seek a vote of no confidence in the government to force a snap election.
Wojciech Olejniczak, the leader of the SLD, said it would submit the motion to parliament on Tuesday.
Mr Lepper claimed his move would bring down the government
Mr Kaczynski sacked Mr Lepper over a major corruption inquiry.
"The decision is based on facts revealed by the Central Anti-Corruption Office regarding large-scale corruption," the prime minister's spokesman said.
Mr Lepper has insisted he is innocent.
Mr Lepper was also sacked from the government last year in a dispute over the budget - but his party was welcomed back later to shore up the coalition.