Italian Prime Minister Silvio Berlusconi has called on legislators not to jeopardise the government out of narrow political interests, as he faces votes of confidence.
Speaking to the Senate, he said Italy needed operational continuity, and ousting him would create a "crisis in the dark".
Those seeking to do so would be unable to form a government, he said.
If he loses, Mr Berlusconi has said there will be early elections.
"I understand those who would challenge the government, opening a crisis leading to fresh elections or at least proposing a different prime minister, whilst being sure of the ability to form a new governing majority," he said in his speech.
"However, I cannot understand the spirit of those who want to trigger, at all costs, a crisis in the dark."
The BBC's Duncan Kennedy in Rome says that, while Mr Berlusconi normally comes out fighting when he is in a corner, that was missing this time and he gave a very calm and measured performance.
He is due to make another speech in the Chamber of Deputies, the lower house, this afternoon.
While he is expected to win in the Senate, the lower house vote will be much tighter and could come down to one or two votes.
Speculation and rumour
He said that under his government Italy had gained a good reputation despite the financial crisis.
"I can say with absolute certainty that Italy is not part of the economic problems in Europe - it has become part of the solution," he said.
He proposed a "legislative pact" with centre-right forces - members of his rival Gianfranco Fini's Future and Freedom for Italy (FLI) political movement, whose defections triggered the crisis, and the opposition Union of the Centre (UDC) party.
"I want to reconstitute the alliance of all the moderate forces that were the origin of our political engagement," he said.
Dozens of the prime minister's supporters have left, depriving him of his automatic majority in the lower house.
Mr Fini says Mr Berlusconi's personal scandals, gaffes and failed policy programme make his position untenable.
He says he has enough votes to unseat Mr Berlusconi, but the numbers are so close no credible observer of these dramatic events is predicting which way it will go, our correspondent says.
Italian media are filled with speculation and rumour about the outcome of votes of confidence in both houses of parliament, he adds.
An investigation has been launched into claims that inducements have been offered to some members of parliament to secure their vote for Mr Berlusconi.
Mr Berlusconi has said that early elections could cause political instability which would lead to a Greek- or Irish-style economic crisis.