ROME, Italy (CNN) -- Italian Prime Minister Romano Prodi sought to shore up his fragile government by calling for a vote of confidence from parliament Tuesday.
Prodi's fragile coalition collapsed after the Udeur Party withdrew support Monday night, wiping out the government's one-vote majority in the Senate.
He told parliament he would seek votes of confidence in both the upper chamber, the Senate, and in the lower, the Chamber of Deputies, where his government holds a comfortable majority. A vote is scheduled for the Chamber of Deputies for Wednesday, while a date for a Senate vote is yet to be announced but could be as early as Thursday.
Should Prodi lose either vote he will be forced to resign.
The crisis began when justice minister Clemente Mastella, of the centrist Udeur party, resigned after his wife was arrested and he was put under investigation for alleged corruption. Mastella withdrew his party from the coalition after complaining that his colleagues in government failed to support him.
Prodi is likely to win the vote in the lower chamber but without the support of the three senators from the Udeur Party he faces a much tougher challenge in the upper chamber, said CNN's Rome Bureau Chief Alessio Vinci.
"Without their support he relies on the vote of senators for life and possibly opposition senators who may want to avoid a crisis, which is unlikely.
"Chances are that he will have to go to the President and tell him he has no governing majority. At that point the President will open consultations with all political leaders, which could last one or two days, after which he will decide to name a new prime minister or dissolve parliament and call for new elections."
President Giorgio Napolitano will hope to stave off elections to allow a electoral law to be passed that will limit the capacity of small parties to hold coalitions to ransom.
Prodi, who has held office for 20 months after one of the closest fought elections in Italian history brought him to power in April 2006, was forced to resign in February of last year, but was reinstated after a vote of confidence in the Senate.
Should Prodi fail to gain the Senate's support this time, it could spell a new period of instability for Italian politics, said CNN's Alessio Vinci.
"It appears that the days of revolving governments could soon be back in Italy, and with it come uncertainty and instability."
He added:"That is too bad, because over the past 20 months this government made good progress towards reigning in public spending and maintaining fiscal discipline.
"Moving forward, the country's leadership should ensure that a new electoral law is adopted before new elections, thus avoiding that the future of a national government of a major western European economy depends on the mood of political parties with less than two percent of national representation." E-mail to a friend
CNN's Rome Bureau Chief Alessio Vinci contributed to this report.