An Italian man who broke Silvio Berlusconi's nose and teeth by striking him with a souvenir model has apologized to the Italian prime minister for his "cowardly and rash act", the attacker's lawyers said.

Police apprehend a man (C) after Italy's Prime Minister Silvio Berlusconi was attacked in downtown Milan December 13, 2009. [Chinadaily.com.cn via agencies]

Berlusconi spent his second night in hospital on Tuesday after the Sunday attack by 42-year-old Massimo Tartaglia, who hurled a small replica of Milan's gothic cathedral at the premier from close range while he signed autographs at the end of a rally.

Tartaglia, who has a history of mental illness, acted alone and without any political or militant interests at heart, his lawyers said in a brief statement released late on Monday.

In a letter sent to Berlusconi, Tartaglia expressed his "heartfelt regret for a superficial, cowardly and rash act in which he did not recognize himself", the statement said.

Berlusconi's allies have portrayed the attack as the fruit of a "climate of hate" swirling around the premier, who frequently accuses "communist" magistrates, the media and leftists of a campaign to bring down his government.

A popular but divisive figure, Berlusconi has for much of the year battled allegations of an improper relationship with a teenage model and parties with escorts and now faces the reopening of several trials against him.

He is expected to remain in hospital for at least another day and is not likely to return to work for 10 days, his personal doctor Alberto Zangrillo has said.