A young Italian man was overpowered by police guards as he attempted to enter Silvio Berlusconi's hospital room in the second security scare in a matter of days.
The 26-year-old managed to gain access to the building at around 2am on Wednesday and took a lift to the eighth floor where the prime minister was recuperating.
Anti-terrorism police confronted the intruder and tackled him as he got within yards of the Italian leader's room.
He was unarmed but police found hockey sticks and two kitchen knives in his car, which was parked in a car park beneath the hospital.
Anti-terrorism officers said the unnamed man appeared to be suffering from "psychological problems" and had "wanted to pay a visit" to Mr Berlusconi.
Mr Berlusconi, 73, had been due to leave Milan's San Raffale hospital yesterday but was unexpectedly kept in for a fourth night because he was suffering from "persistent pain" and was having to eat through a tube.
Paolo Bonaiuti, Mr Berlusconi's spokesman, said he was still suffering from pain to his neck, as well as a broken nose, two smashed teeth and deep cuts to his face.
Massimo Tartaglia, 42, appeared in court in Milan charged with throwing a souvenir model of Milan's famous cathedral into Mr Berlusconi's face.
The attack has pitched Italy's already acrimonious political discourse into a frenzy of impassioned recrimination and accusation.
Mr Berlusconi's supporters in his People of Freedom bloc have blamed the Left-wing opposition of creating a "climate of hate" which enabled such an attack to take place.
When the leader of the biggest opposition party, Pierluigi Bersani, visited Mr Berlusconi in hospital this week, a woman yelled at him: "You stirred them up!"
The Left countered by saying Mr Berlusconi had made himself a legitimate target of anger by trying to change the law to avoid a pair of corruption trials and by labelling Italian judges and magistrates "Communists", alleging that they are conducting a vendetta against him.
Italians' widely differing response to the assault was summed up by two opposing images.
A middle-aged man was photographed outside the hospital in Milan holding up a handwritten placard which read: "Berlusconi, you are a legend. You will go down in history. Thank you for what you have done for our country." But in nearby Turin, opponents of the government scrawled on a wall: "A medal for Tartaglia".
The interior minister, Roberto Maroni, angrily denounced online messages of support for the assault, saying they amounted to a "growing personal campaign" which risked provoking "a spiral of emulation".
Renato Schifani, a close Berlusconi ally and the speaker of the Senate, said tensions had reached a dangerous pitch.
"I am very worried by this escalation of hatred against a single person," he said.
As Italy's president, Giorgio Napolitano, appealed for calm, the Vatican's semi-official mouthpiece, the Osservatore Romano newspaper, said the incident was an "alarm bell" that should compel politicians to tone down the bitterness of their rhetoric.
Italians are acutely aware that the country was torn apart by in-fighting during the 1970s and 1980s, when factions from the extreme Left and Right carried out a tit-for-tat series of shootings and bombings.
While there was as yet "no comparison" to be made with that era, parliament was in danger of "going up in flames" as a result of the increasingly vitriolic political debate, said La Stampa newspaper.
The president of a think tank, Ferdinando Adornato, said: "Italy is a country which has lived through a civil war, although fortunately only a verbal one, for years. The comparison with the 1970s is out of place, but there is a risk that this verbal civil war could evolve from words, to actions."