In addition to being simple, it's traditional: the last such jail-emptying exercise took place in 1990. This time again, prisoners serving terms of three years or less are being released, with the exception of convicts guilty of Mafia crimes, terrorism, sexual violence or (a little oddly) usury. With about 62,000 prisoners crammed into jails meant for a fraction of that number, justice minister Clemente Mastella hopes to see the back of nearly one-third of the state's guests.

But to the undisguised glee of Silvio Berlusconi's opposition, things began to go wrong at once, with a prisoner in his 50s from the city of Udine going straight from jail to the home of his ex-wife and attempting to murder her. Others were speedily re-arrested in the act of smashing the window of a pizzeria in Genoa, stealing cars in Trieste and Brescia, and, from a smart city centre store in Bologna, three pairs of jeans.

Voices on both right and left attacked the government for failing to put in place mechanisms to help prisoners readjust to life outside. Antonio Mazzocchi, an MP with the right-wing National Alliance, suggested the first 700 prisoners re-arrested should be put under house arrest . . . in the homes of the MPs who had voted in favour of the measure.

Prisoner-advocate organisations protested that facilities to help released prisoners risked being overwhelmed. "It's like opening a dam, " commented Francesco Gesualdi of Pisa's New Development Model Centre. "A smaller number would have been more manageable."

An extra headache for the governement was the 5,393 foreign prisoners expected to be freed, the majority of whom are thought to be illegal immigrants. Under current immigration law, once out of jail these so-called clandestinimust either be issued with a notice to quit the country within five days . . . in practice an invitation to disappear . . . or be consigned to one of the notorious temporary reception centres for illegal immigrants which are already bursting at the seams.

There are also fears that a number of potentially dangerous Islamist extremists are among those streaming out of the jails. La Stampa newspaper named 20 such prisoners who it claimed pose a possible threat.