Romano Prodi said today his victory in Italy's general election this week was secure despite demands by current Prime Minister Silvio Berlusconi for ballot checks.
"I don't have any fear whatsoever that the result will be overturned. It is a clean victory," Mr Prodi told foreign reporters.
The closest election in Italy's post-war history saw Mr Prodi win a wafer-thin two-seat majority in the upper house Senate and prevail in the lower house by just 25,000 votes out of 38.1 million cast.
Mr Berlusconi, however, has said he will only concede defeat after disputed ballots have been checked, a position that Mr Prodi mocked.
"It's a curious situation that Berlusconi protests when he has in his hands all the control, all the transmission of the data, all the technical apparatus," Mr Prodi said.
"It means he doesn't trust himself, it's a kind of identity crisis."
In a news conference at Italy's foreign press association, Mr Prodi, who has already been congratulated on his victory by several European leaders, was keen to present himself as prime minister-in-waiting.
He said that once in power he would "very quickly" put his election programme into action by cutting labour taxes, changing current laws on immigration and conflict of interest and realigning Italian foreign policy more closely with Europe
Mr Prodi said he could probably form a new government only in the second half of May once a new Italian president had been elected.
"The constitutional decision is that probably it will be the new president who will decide to give me the responsibility to govern," said Mr Prodi. "So we would have to wait until the second half of May."
Asked when he would prepare the formation of his new government, he said: "I've already started. We have already had our first meetings."
"For now, no one can say they have won," Mr Berlusconi earlier told a news conference when he urged Mr Prodi to form a German-style grand coalition in which left and right would share power.
"I think that maybe we should take the example from some other European country, perhaps an important country like Germany, to see if it would not be the case to unite forces and govern in harmony."
Mr Prodi denied his rival's assertion that there were "many, many murky aspects" to the vote and rejected his offer of a left-right alliance, saying he had a clear mandate to govern.
Italy's electoral system, which gives a premium of extra seats to a winning coalition, means Mr Prodi's side has 348 seats in the lower house, compared with 281 for Mr Berlusconi's centre-right bloc. His majority in the upper house, where seats are allocated differently, is just 158 against 156 for the centre-right.
"It's clear that I won the elections. The margin was narrow, but the result was clear. There is no problem," he told French radio in part of a charm offensive with the international press.