Italian Prime Minister Romano Prodi will face two votes of confidence in parliament following the resignation of an ally from his coalition government.
Romano Prodi came to power as the winner of the April 2006 election
The vote in the Chamber of Deputies will take place on Wednesday, while the Senate vote has not yet been scheduled.
Earlier, Mr Prodi briefed the lower house about the crisis, which has seen the former Justice Minister, Clemente Mastella, withdraw from the coalition.
Mr Mastella quit last week after being implicated in a corruption inquiry.
His centrist Udeur party also has three seats in the upper house, the Senate, and its withdrawal has cost Mr Prodi his majority of one.
Plea for continuity
In a defiant speech in the Chamber of Deputies, Mr Prodi said his government would seek a vote of confidence in both houses of parliament to allow it "to respect our commitments to the voters".
"We need continuity of action above all at a moment when the world economy is faced with negative developments," he said.
"Important projects await us, which we responsibly started without thinking that occasional decisions could put them into question."
The vote in the lower house, where Mr Prodi's centre-left coalition has a comfortable majority, is scheduled for 1500 (1600 GMT) on Wednesday. No date has been set for the vote in the Senate, but reports suggest it could be as early as Thursday.
Mr Mastella threatens to oppose Mr Prodi in any confidence votes
The environment minister, Alfonso Pecoraro Scanio, is also due to face a vote of confidence in the Senate on Wednesday for his handling of the rubbish crisis in Naples.
Correspondents say defeat for him would further undermine Mr Prodi's position.
Although the prime minister said he believed he would survive the confidence votes, his chances were weakened earlier this week when Mr Mastella said his Udeur party would probably vote against the government.
To survive without his former ally's support in the upper house, Mr Prodi may have to rely on the seven unelected life senators, mostly former presidents, who tend to back him.
The BBC's Christian Fraser in Rome says that even if Mr Prodi is forced to resign, the path for Italy is still unclear.
There is widespread agreement among politicians - even among the prime minister's opponents - that the country needs new electoral laws, he adds.
Under the current system rushed in by the former Prime Minister, Silvio Berlusconi, smaller parties with a handful of seats hold the balance of power.
Even Mr Berlusconi, now leader of the opposition, would have great difficulty forming a stable majority to rule if he was to win an election, our correspondent says.
Analysts say it is much more likely that if Mr Prodi does go, President Giorgio Napolitano will call an interim government of technocrats to force through such reforms.