Italian Prime Minister Silvio Berlusconi says he is optimistic about winning a confidence vote but if he loses, it would mean early elections.
A date has now been set for the confidence vote - 14 December.
Mr Berlusconi believes he would win any national vote, although the latest opinion poll puts his approval rating at 35%.
He has been beset by defections from his coalition and allegations about his behaviour.
Recently the prime minister denied improper conduct in the case of a teenage nightclub dancer who was released from a police cell following his intervention.
Four more members of his coalition resigned on Monday, including undersecretary Roberto Menia who said he was worried about the "moral message" that the government was sending out.
They are all backers of Mr Berlusconi's former ally, parliamentary speaker Gianfranco Fini, who sparked this political crisis when he and 40 other lawmakers left the prime minister's party in July.
Mr Berlusconi told reporters on Wednesday that starting this crisis was an "irresponsible act".
But he said: "If we win the confidence (vote) we will carry on working, otherwise we go to the polls".
The date for the confidence vote - in both chambers of parliament - was agreed at talks on Tuesday night.
If the prime minister loses in either vote, he would be forced to resign.
He still has a majority in the Italian Senate but not in the lower house of parliament - where many analysts expect him to be defeated.
Most opinion polls suggest Mr Berlusconi would probably win an early election, but that he might not get a majority in the Senate, which would make it almost impossible to govern.
An IPR opinion poll posted on the website of the left-leaning newspaper La Repubblica said his approval ratings were down to 35%, down two points from last month and 10 points lower than in November 2009.
President Giorgio Napolitano has advised Italy's political class to act responsibly. He said the current turmoil in financial markets could create further uncertainties for the country.