Romano Prodi has once again urged Italian Prime Minister Silvio Berlusconi to admit defeat in the nation's general election.
Prodi looks set to be confirmed as the election winner
Mr Prodi's call came after the interior ministry sharply reduced the number of contested ballots from 80,000 to 5,000.
"He must acknowledge how things went," said Mr Prodi, "and apologise as well after what he said about fraud."
Mr Berlusconi alleged election fraud shortly after the 9-10 April vote but promptly withdrew his allegations.
The centre-right leader remained defiant, describing himself as a "fighter" and saying he was hopeful of being declared the winner.
In a letter to the Corriere della Sera newspaper on Saturday, he indicated that he was not prepared to give up.
"At least on the basis of the popular vote, there's no winner and no loser," he wrote.
He also proposes a short-term coalition with his rival to "meet the country's immediate institutional, economic and international timetable".
Mr Prodi, who heads the centre-left coalition, has already rejected such a suggestion.
Official results of the parliamentary election have yet to be announced but are likely to confirm Mr Prodi's narrow victory.
With the revised number of contested ballots, the interior ministry said the figure was too low to affect the poll result.
The ministry said there had been a mix-up - invalid or blank ballots had been mistakenly lumped together with the contested votes.
Mr Prodi claimed victory in the polls after official results showed he had won just enough seats to control the Senate (upper house) after having already won a lower house majority.
The count gave Mr Prodi 158 Senate seats, against 156 for Mr Berlusconi. Mr Prodi won the lower house by about 25,000 votes in the election on Sunday and Monday.
The results are considered provisional until Italy's supreme court, the Corte di Cassazione, rules on their validity. This is expected to happen next week.
The new parliament is scheduled to convene on 28 April.