Prime Minister Silvio Berlusconi said any trial involving him would be a "farce"
By Duncan Kennedy
BBC News, Rome
No one is above the law, not even a prime minister.
That is the conclusion of one of the most eagerly awaited court decisions in recent Italian history.
The country's Constitutional Court has ruled that Silvio Berlusconi and three other people in public life - the president of the republic and the two parliamentary speakers - should not have immunity from prosecution while they are in office.
But, just like the country as a whole, it seems the judges were divided over the issue. The judges voted nine to six against the law.
So what are the implications? Well, it is best to divide them into two.
Firstly, the legal implications. In theory, and nobody has really confirmed this yet, the ruling should mean that at least two court cases against Mr Berlusconi will now reopen.
Snubbing his nose at the highest court in the land may have unwelcome consequences
They were suspended last year after the highly controversial immunity law was passed.
The cases include one in which the prime minister was accused of handing a $600,000 (£375,000) bribe to his former tax lawyer, David Mills, to give false evidence in two separate trials.
Mr Mills was convicted and given a four-and-a-half year jail sentence. He is appealing.
Another possibility is that Mr Berlusconi may attempt to get the constitution rewritten to reinstate immunity for the four top public offices.
That would be a complicated parliamentary procedure and might even require a referendum. At the very least, it would take a year to achieve.
The political ramifications of Wednesday's ruling are even less clear.
Mr Berlusconi himself has said he will not resign, calling the constitutional court a "tool of the left". That leaves the matter in the hands of his political allies, his coalition partners and the official opposition.
So far as his allies are concerned, some have already come out and said they will stand by him.
Senator Lucio Malan, from Mr Berlusconi's People of Freedom Party, says there is no need for the prime minister to resign and force an election, as all opinion polls already give him strong backing.
That is true, up to a point.
Mr Berlusconi's ratings have just dropped below 50% for the first time since coming back to power, confirming a recent downward trend, but they are still far from any danger zone.
When it comes to his coalition partners, especially the Northern League, they too appear to lack the appetite to face new elections by bringing down the prime minister.
The League's colourful leader, Umberto Bossi, has met Mr Berlusconi and came out saying: "I found him strong, and that pleased me. I found him resolved to fight."
Mr Bossi's party is vital to all this, so its decision to continue its support could determine the course of events.
As for the centre-left opposition Democratic Party (PD), it called for Mr Berlusconi to resign if he lost the immunity case.
The PD says it would be absurd for Mr Berlusconi to try to carry out his official duties while standing trial in a series of court cases.
The trouble the PD has, however, is that it simply does not have the power, unity or seats in parliament to influence events.
Badges of pride
Wednesday's court decision caps a wretched few months for Mr Berlusconi.
Ever since the incendiary comments in April from his wife, Veronica, that he needed help because of his unhealthy interest in young women, he has been ricocheting back and forth between a series of personal scandals.
Patrizia D'Addario, an escort, says she spent the night with Mr Berlusconi
Claims that he spent the night with an escort have been one of the higher-end allegations.
Mr Berlusconi never quite denied the nature of the woman's profession, but has insisted he never parted with a cent of his multi-billion euro fortune.
The prime minister's unconventional private life has earned him the combined wrath of everyone from the political opposition to the Catholic Church.
But it has not led to a haemorrhaging of public support.
Personal scandals in Italy impinge on the public psyche in ways different from other countries.
Mr Berlusconi has even worn some of them as badges of pride, deftly reading the public's largely tolerant mood and capitalising on the fact that there is no real political opposition to him.
However, his adroit political antennae may yet have to be retuned following the immunity ruling.
As Mr Berlusconi enters a new era without the shield of legal immunity, his armour may yet not be pierced, but it has been dented
Thumbing his nose at the highest court in the land may have unwelcome consequences for him.
Nevertheless, Mr Berlusconi is known for his combative approach to establishment institutions and he may well relish another confrontation, even though he has just turned 73.
That is because the prime minister is a man in search of a legacy.
He has spent much of the past year attempting to burnish his reputation as a world statesman abroad - helping rehabilitate the Libyan leader, Col Muammar Gaddafi - and as a patrician at home - personally taking charge of the response to the recent earthquakes in Abruzzo and floods in Sicily.
Much of that had already been undone by the current scandals.
Now, as he enters a new era without the shield of legal immunity, his armour may yet not be pierced, but it has been dented.