Silvio Berlusconi's followers today pounced on the attack in which he was injured, blaming his political enemies and courtroom adversaries for inciting the violence, and announcing plans for new restrictions on demonstrations and the internet.

In a tumultuous debate, the leader of Berlusconi's parliamentary party in the chamber of deputies, Fabrizio Cicchitto, said: "The hand of he who attacked Berlusconi was primed by a pitiless campaign of hatred." He went on to name the organisations and individuals he said were behind it.

Top of the list was the group that owns the daily newspaper La Repubblica and the weekly magazine L'Espresso, which earlier this year made the running in coverage of successive sex scandals involving Italy's prime minister. Next came a new, radical daily, Il Fatto, which Cicchitto described as "the morning paper of the prosecution service". After losing his immunity from prosecution in October, Berlusconi now faces trial for bribery and fraud.

The leader of the majority in the lower house then singled out Marco Travaglio, author of a recently re-published book about Berlusconi's links with the mafia, whom he denounced as a "media terrorist". Finally, Cicchitto pointed the finger at "certain prosecutors who go on television" and two of Italy's opposition parties, including the biggest, the Democratic party, whose leader, Pierluigi Bersani, visited Berlusconi in hospital on Monday.

Bersani told parliament: "The risk is that someone is dressing up as a fireman in order to play the arsonist." The leader of the other group named, Antonio Di Pietro of the Italy of Principles party, said: "We will not be intimidated. Ours is not an opposition of hatred, but of love for our country." His words were lost on the members of Berlusconi's Freedom People movement, who walked out of the chamber after he got up to speak. Using some of the most inflammatory language heard in the Italian parliament in recent years, one of Di Pietro's MPs shouted after them that they were "mafia people".

The clash erupted on a day when the interior minister, Roberto Maroni, announced that Thursday's cabinet meeting will discuss two new bills, one dealing with demonstrations and the other with "groups on the internet who laud the prime minister's assailant". These, he said, "represent an out-and-out instigation to crime. We are considering shutdowns, with solutions I intend to table at the next cabinet meeting". The wisdom of closing websites was questioned, however, by one of his own cabinet colleagues, the defence minister, Ignazio La Russa.

Maroni told parliament that Sunday's attack, which left the prime minister with a broken nose, two chipped teeth and cuts on his top lip, had been premeditated. Today , a witness came forward to say he thought the attacker, Massimo Tartaglia, who has a long history of mental instability, might have been passed the plaster souvenir he hurled at Berlusconi. Andrea Di Sorte, a top organiser of Berlusconi's political clubs, said: "I saw that there was a movement behind, as if he were wriggling to get hold of something from someone who, obviously, I didn't see."

The prime minister is due to leave hospital "with a recommendation not to take on demanding public engagements for at least two weeks", said his personal doctor, Alberto Zangrillo. He said the attack had aggravated a neck complaint from which the prime minister already suffered and that he was being given more painkillers.

The Freedom People's website carried a message from Berlusconi thanking all those who had wished him well, and adding: "Love always wins out over envy and hatred." But Zangrillo gave a strikingly different account of his patient's humour. He said the state of his morale was "worrying", though improving, and that Berlusconi felt "deep bitterness over what has happened", adding cryptically "and over certain things [that happened] afterwards".