Mr. Mattarella made clear that Italy, facing critical issues such as the euro and migrant policies in Europe, and needing to approve a budget and prevent automatic tax increases at home, could no longer wait while the right-wing League party, the anti-establishment Five Star Movement or others ironed out an agreement.
“The unwillingness of all of them was confirmed this morning,” he said, adding that there wasn’t “any possibility to form a majority government.”
Mr. Mattarella, who usually has a ceremonial role but is imbued by the Italian Constitution with great power during moments of political chaos, said the government led until this point by Prime Minister Paolo Gentiloni was appreciated, but no longer viable. “It’s necessary to give life to a new government,” he said. “One can no longer wait.”
More than half of Italians gave their support to the League and the Five Star Movement on March 4, but neither won enough votes to win a majority in Parliament. Mr. Mattarella argued that the parties would have more time to work out their disagreements while a “neutral” government did the actual governing.
Mr. Mattarella, a former member of Parliament, a defense and education minister and a judge on Italy’s constitutional court, became president in 2015 and since then has sought to stay above the political fray.
In keeping with his trademark aversion to drama, Mr. Mattarella sought to avoid a return to the polls in the summer or fall, which could produce the same impasse. He said he hoped the parties could reach an agreement by the end of December, when his caretaker government would expire. If not, he said, elections should be held in the new year.
Italy’s leading politicians did not want to wait that long.
The leaders of the Five Star Movement, Luigi Di Maio, and the League, Matteo Salvini, met on Monday for the first time since the elections to pick a date for new elections.
“July 8 is the first possible date to vote, and Di Maio also agrees,” Mr. Salvini told reporters.
On Monday morning, Mr. Salvini, whose party won the most votes in a center-right coalition with former Prime Minister Silvio Berlusconi, urged Mr. Mattarella to give his alliance a mandate to seek enough support in Parliament to form a government. But with the coalition about 50 seats short of a majority, Mr. Mattarella did not bother.
Mr. Salvini then rejected the president’s offer on Monday evening.
“Mattarella wants a ‘neutral government’? Please,” Mr. Salvini, a gifted campaigner, wrote on Twitter, adding that Italy needed a government “that defends in Europe the principle ITALIANS FIRST.”
Mr. Salvini seemed to anticipate the president’s decision, taking to Facebook earlier to prepare his base for coming elections. He told them that more migrants were already coming and that if the negotiations failed, “we will come to ask you for that 2, 3, 4 percent more votes which would give us the chance to govern alone for five years, without asking permission of anyone.”
Mr. Mattarella had given the Five Star Movement time and space to find support on the right, with the League, and with the center-left Democratic Party that it spent much of the last few years insulting. But after 65 days of negotiations, he apparently had had enough.
Early in the morning, the president met with Mr. Di Maio, 31, who, to reinforce his anti-establishment appeal, drove to the meeting in a small white Citroën.
Speaking to reporters afterward, Mr. Di Maio said, “We are not willing to support a confidence vote for a technical government.” Arguing that he was not to blame for the stalemate, he said, “I was never the impediment.”
Over months of talks, Mr. Di Maio, who is facing his party’s self-imposed term limits, failed to peel Mr. Salvini away from his center-right coalition partner, Mr. Berlusconi, with whom the Five Star Movement refuses to join forces. Late last month he slammed the door shut on any deal with the League.
“Now I want to say it officially,” he said at the time. “For me, any talks with the League end here. It is clear that a government with the center-right is no longer a pursuable hypothesis.”
But on Monday, with the president’s decision only hours away, he scrambled to reopen the door to talks.
In what he called a “new phase” of the talks, Mr. Di Maio said he was still willing to find an agreement with Mr. Salvini on a prime minister they could both support and who would push their priorities, including a universal basic income, anti-corruption laws and a rollback of pension reforms.
After the president’s remarks, Mr. Di Maio reiterated on Twitter that he would vote “No confidence in a ‘neutral’ government.”
A failure of Mr. Mattarella’s temporary, technocratic government to win a confidence vote in Parliament would lead to new elections and, European leaders fear, upset the markets.
Mr. Di Maio, a leader of a web-native and ideologically ambiguous party that has fed on the discontent of Italian voters, especially in the country’s poorer south, relished a vote that he characterized as a “run off” between the Five Star Movement and the League.
“It’s clear that there are two political realities competing to lead the country,” he said. “And the Italians will decide.”