He was left with no choice but to quit after the new parliament on Saturday elected speakers for the lower and upper houses who are both from Prodi's centre-left coalition -- communist Fausto Bertinotti and Franco Marini of the centrist Margherita party.

Berlusconi occupied the prime minister's office for the longest continuous period for half a century. He was renowned, or infamous, for his verbal excesses, repeated brushes with the law, pro-Americanism, domination of the media and colossal wealth.

Italy's political transition is already under way, and the two speakers have made it clear they want dialogue between the parties that contested the April 9-10 general election, the closest in living memory.

Berlusconi, who contested the centre-left's razor-thin election victory -- by just 25,000 votes -- every step of the way, has now opened a new front in the continuing battle by challenging the legality of his adversaries' political timetable.

While the centre-left wants Ciampi, whose presidential term expires on May 18, to ask Prodi to form a government before seeking parliamentary approval, Berlusconi claims that is the task of the next president, whom parliament must elect.

Politicians locked horns on Monday over the issue, as Prodi huddled with coalition partners to fine-tune his government line-up.

The battle to replace the head of state -- who has the power to appoint the prime minister, dissolve parliament and call elections -- intensified amid media reports that Prodi's coalition favours former prime minister Massimo D'Alema of the Democrats of the Left (DS) party.

"They want to take everything," raged Il Giornale, a newspaper owned by Berlusconi's family, over the prospect that D'Alema would succeed Ciampi as president, after Prodi's candidates for the speakerships of both houses of parliament were approved.

"We represent 50 percent of the country, and so we can only talk about a president who will not come under the influence of the left," Berlusconi aides quoted him as saying, adding that the president should not be someone who would shore up the left wing if its unity starts to crumble, according to the daily La Repubblica.

D'Alema himself refused to comment, and Prodi did not confirm or deny that he would be the candidate.

But the leaders of the DS, the largest party in the Union, have told Prodi that they feel they deserve a major institutional post after the parliamentary speakerships went to other parties, Italian newspapers said on Monday.

In the event of a no-confidence vote -- a by no means impossible prospect given Prodi's wafer-thin majority -- it would be up to the president to decide whether to simply appoint the premier for a new term or call fresh elections.

Meanwhile Prodi, 66, has been meeting with leaders of the various parties in his broad coalition, ranging from communists to centrists, to discuss the formation of his government.

The former European Commission president said his cabinet line-up would be ready by the end of the week.

"My team is not yet ready because we have a few more days for discussion," he said Monday. "There are a lot of things we should talk about, and this should be done calmly and serenely."

Sarkozy, the son of a Hungarian immigrant, has had to defend himself against charges he is running a xenophobic drive to poach votes from far-right National Front leader Jean-Marie Le Pen, who launched his presidential campaign on Monday.

"All democrats should welcome it if the National Front's score falls," Thierry Mariani, a deputy and Sarkozy ally, said on Monday. Le Pen shocked France in 2002 by finishing second to President Jacques Chirac in the first round of voting.

Sarkozy says the bill aims to attract a new generation of skilled workers who would embrace French values and traditions, thus easing the tense race relations that led to last autumn's suburban riots by youths mostly of immigrant origin.

It would create a three-year "skills and talents" residence permit to attract skilled workers. It would also make it harder for resident immigrants to bring family here, force newcomers to take French and civics lessons and end their automatic right to a long-term residence permit after 10 years in France.

CRITICS AND RIVALS

Sarkozy says his bill would allow France to select its immigrants, as other industrialized countries do, rather than take anyone who comes. This should help reduce racism, he says.

Left-wing critics say the law will not work, will stigmatize foreigners, discriminate against the poor and undermine France's traditional role as a haven for the persecuted.

Sarkozy's own immigrant father might have failed to qualify for French nationality had his son's rules applied when he fled Communist-controlled Hungary in the late 1940s, they say.

More than 5,000 people marched through Paris on Saturday to protest against the bill.

Separately, Catholic Cardinal Jean-Pierre Ricard and Jean- Arnold Clermont, head of the French protestant federation, met Prime Minister Dominique de Villepin to express their concern about some measures in the draft law.

On the far right, Le Pen told a rally on Monday that the tougher line from Sarkozy and a far-right rival showed that his anti-immigrant views were gaining ground in France. Many held up a map of France with the slogan "Love it or leave it."

Le Pen's far-right rival Philippe de Villiers began his presidential campaign this month with blistering attacks on what he calls the Islamisation of France and a demand for an end to all mosque construction around the country.

Political analysts say Sarkozy is courting far-right voters after ensuring Paris climbed down this month over a labor law reform that sparked sometimes violent mass protests. His presidential prospects could suffer if disillusioned voters switch to far-right parties as a result.

The bill comes as Chirac and Villepin, both badly mauled by the crisis over the new law for young workers, are struggling to show they can still govern despite the setback.

On some streets in LA's downtown, including the garment district, the shutters remained closed on every store.

Many small business owners opted to shut down for the day as gesture of support for their immigrant workforce.

Some posted a notice saying: "United in peace: out of respect for members of our community our stores are closed today, May 1."

'Forgotten contribution'

"Everybody forgets how much we contribute to the economy," said Vincente Amador, a small business owner who gave his staff of seven workers the day off to join the demonstration.

LA schools were officially open, but some reported truancy rates of up to 30%.

Others, in areas close to the demonstrations, chose to leave their gates chained for the day.

At a march and rally, protestors wearing white waved the American flag and chanted "Si se puede!" - Spanish for "Yes it can be done!"

Others carried banners urging the US Congress to grant citizenship to illegal immigrants.

"We as immigrants should unite and come together because my parents came here illegally," said Sal Diaz, one of the protestors.

"If it wasn't for them, I wouldn't be where I am now, in college, graduated and all."

'Swamped by migrants'

A handful of people took to the streets to object to the assertion, by illegal immigrants, that they should be made citizens of the United States.

"They come here and swamp our social services," said Betty Jo Young. "Our country will be a Third World country if people don't stand up and say 'That's enough'."

Wiley Drake added: "The boycott as I understand it is to make illegal migrant workers legal in America. That's wrong, it's against the law and it's unprincipled."

The day of action did not receive universal support from immigrant workers.

The United Farm Workers' Union urged its members to take part in rallies after work, to avoid being fired.

The union supports a comprehensive immigration reform package and a measure that would legalise 1.5 million farm workers over the next five years.

Giev Kashkooli, an officer with the union, said if the US turned its back on the immigrant workforce, the consequences would be far-reaching:

"Americans would not be eating fresh fruit and produce, it's very, very simple.

"If they really could figure out a way to deport 10-12 million people the agricultural economy as we know it would totally collapse."

Future voters

A rallying call heard at immigration rallies around the country has been "Today we protest and tomorrow we vote".

Much has been made of the prospect of a rapidly emerging immigrant movement with political teeth. With millions taking to the streets, the rallies are reminiscent of the civil rights protests of the late 1960s.

"There's a whole lot of truth to that," said Abel Valenzuela, an associate professor of urban planning and Chicano studies, at the University of California.

"I think congressmen and women in Washington DC better be paying a whole lot of attention to that."

Much attention is being paid to the attitudes of young Hispanic Americans. They are said to be angry and motivated.

"Of the Latin population below 18, 86% of them are US-born and documented," said Prof Valenzuela.

"That group is becoming exposed to the power of organising, of politics, of marches and protest. And research shows they're more likely to vote.

"So in a few years you're going to see these people actually going out there and voting. I think in many ways what we're seeing on the streets today will, in fact, have an impact in the future."

The affair began with anonymous charges in 2004 that Sarkozy and other politicians had accounts in a Luxembourg-based finance house, Clearstream, and linked them to a bribe-ridden sale of French frigates to Taiwan in 1991.

The list quickly proved bogus. A judicial inquiry has since concentrated on finding out who authored it and whether top government officials delayed clearing the accused left- and right-wing politicians' names as a way of discrediting them.

Villepin and President Jacques Chirac have denied any involvement in the scandal. Villepin and Sarkozy are in open competition for the nomination as the main conservative candidate in the 2007 presidential election.

Villepin on Tuesday ruled out holding early elections over the scandal.

The scandal gained steam last Friday, when Le Monde newspaper quoted a senior intelligence official who investigated the scandal as saying Villepin had told him that Chirac wanted the confidential probe to focus on Sarkozy.

The official, Philippe Rondot, denied the report on Tuesday.

"Villepin never asked me to get interested in politicians," Le Figaro newspaper quoted Rondot as saying.

Does television cause crime? The idea that people copy the violence they watch is debated endlessly by criminologists. But this column concerns an odder and perhaps more interesting idea: if crime leaps out of the box, it is not the programmes that are responsible as much as the material in between. It proposes that violence emerges from those blissful images of family life, purged of all darkness, that we see in the advertisements.

Let me begin, in constructing this strange argument, with a paper published in the latest edition of Archives of Pediatrics and Adolescent Medicine. It provides empirical support for the contention that children who watch more television eat more of the foods it advertises. "Each hour increase in television viewing," it found, "was associated with an additional 167 kilocalories per day." Most of these extra calories were contained in junk foods: fizzy drinks, crisps, biscuits, sweets, burgers and chicken nuggets. Watching television, the paper reported, "is also inversely associated with intake of fruit and vegetables".

There is no longer any serious debate about what a TV diet does to your body. A government survey published last month shows that the proportion of children in English secondary schools who are clinically obese has almost doubled in 10 years. Today, 27% of girls and 24% of boys between 11 and 15 years old suffer from this condition, which means they are far more likely to contract diabetes and to die before the age of 50. But the more interesting question is what this diet might do to your mind. There are now scores of studies suggesting that it hurts the brain as much as it hurts the heart and the pancreas. Among the many proposed associations is a link between bad food and violent or antisocial behaviour.

The most spectacular results were those reported in the Journal of Nutritional and Environmental Medicine in 1997. The researchers had conducted a double-blind, controlled experiment in a jail for chronic offenders aged between 13 and 17. Many of the boys there were deficient in certain nutrients. They consumed, on average, only 63% of the iron, 42% of the magnesium, 39% of the zinc, 39% of the vitamin B12 and 34% of the folate in the US government's recommended daily allowance. The researchers treated half the inmates with capsules containing the missing nutrients, and half with placebos. They also counselled all the prisoners in the trial about improving their diets. The number of violent incidents caused by inmates in the control group (those taking the placebos) fell by 56%, and in the experimental group by 80%. But among the inmates in the placebo group who refused to improve their diets, there was no reduction. The researchers also wired their subjects to an electroencephalograph to record brainwave patterns, and found a major decrease in abnormalities after 13 weeks on supplements.

A similar paper, published in 2002 in the British Journal of Psychiatry, found that among young adult prisoners given supplements of the vitamins, minerals and fatty acids in which they were deficient, disciplinary offences fell by 26% in the experimental group, and not at all in the control group. Researchers in Finland found that all 68 of the violent offenders they tested during another study suffered from reactive hypoglycaemia: an abnormal tolerance of glucose caused by an excessive consumption of sugar, carbohydrates and stimulants such as caffeine.

In March this year the lead author of the 2002 report, Bernard Gesch, told the Ecologist magazine that "having a bad diet is now a better predictor of future violence than past violent behaviour ... Likewise, a diagnosis of psychopathy, generally perceived as being a better predictor than a criminal past, is still miles behind what you can predict just from looking at what a person eats."

Why should a link between diet and behaviour be surprising? Quite aside from the physiological effects of eating too much sugar (apparent to anyone who has attended a children's party), the brain, whose function depends on precise biochemical processes, can't work properly with insufficient raw materials. The most important of these appear to be unsaturated fatty acids (especially the omega 3 types), zinc, magnesium, iron, folate and the B vitamins, which happen to be those in which the prisoners in the 1997 study were most deficient.

A report published at the end of last year by the pressure group Sustain explained what appear to be clear links between deteriorating diets and the growth of depression, behavioural problems, Alzheimer's and other forms of mental illness. Sixty per cent of the dry weight of the brain is fat, which is "unique in the body for being predominantly composed of highly unsaturated fatty acids". Zinc and magnesium affect both its metabolism of lipids and its production of neurotransmitters - the chemicals which permit the nerve cells to communicate with each other.

The more junk you eat, the less room you have for foods which contain the chemicals the brain needs. This is not to suggest that food advertisers are solely responsible for the decline in the nutrients we consume. As Graham Harvey's new book We Want Real Food shows, industrial farming, dependent on artificial fertilisers, has greatly reduced the mineral content of vegetables, while the quality of meat and milk has also declined. Nor do these findings suggest that a poor diet is the sole cause of crime and antisocial behaviour. But the studies I have read suggest that any government that claims to take crime seriously should start hitting the advertisers.

Instead, our government sits back while the television regulator, Ofcom, canoodles with the food industry. While drawing up its plans to control junk food adverts, Ofcom held 29 meetings with food producers and advertisers and just four with health and consumer groups. The results can be seen in the consultation document it published. It proposes to do nothing about adverts among programmes made for children over nine and nothing about the adverts the younger children watch most often. Which? reports that the most popular ITV programmes among two- to nine-year-olds are Dancing on Ice, Coronation Street and Emmerdale, but Ofcom plans to regulate only the programmes made specifically for the under-nines. It claims that tougher rules would cost the industry too much. To sustain the share values of the commercial broadcasters, Ofcom is prepared to sacrifice the physical and psychological wellbeing of our children.

At the European level, the collusion is even more obvious. Last week, Viviane Reding, the European media commissioner, spoke to a group of broadcasters about her plans to allow product placement in European TV programmes (this means that the advertisers would be allowed to promote their wares during, rather than just between, the programmes). She complained that her proposal had been attacked by the European parliament. "You have to fight if you want to keep it," she told the TV executives. "I would like to make it very clear that I need your support in this."

I spent much of last week trying to discover whether the Home Office is taking the research into the links between diet and crime seriously. In the past, it has insisted that further studies are needed, while failing to fund them. First my request was met with incredulity, then I was stonewalled. Tough on crime. To hell with the causes of crime.