Italy's Silvio Berlusconi began community service for tax fraud on Friday in a spectacular fall from grace for the flamboyant ex-premier, who will likely seek political gain from the symbolic punishment.

The billionaire tycoon, who was convicted last year and has been expelled from parliament, has been ordered to work once a week for up to a year as a volunteer in a hospice for Alzheimer's patients near Milan.

"To prison!" a trade unionist protester in a clown hat shouted, as Berlusconi arrived at the clinic with his security detail in a chauffeur-driven car, wearing a blue suit with an Italian flag badge.

"We Italian workers have one dream in our hearts: Berlusconi in San Vittore!" he shouted, referring to a Milan prison, before being led away by police.

The Catholic Church-run hospice in Cesano Boscone has said it will not allow Berlusconi to use his stint for political grandstanding in front of the world's media and will treat him like any other volunteer.

The disgraced politico has dominated Italian politics for two decades and is leading a campaign for European Parliament elections despite being barred from running and his party is expected to get 20 percent of the vote.

Massimo Restelli, head of the hospice's care services, told the La Repubblica daily that Berlusconi's introduction would be "gradual" so that he and the elderly patients can get used to each other.

"It will be small steps so as not to make any mistakes. And then he could do all sorts of things. He could help with meals, which are tricky because sometimes you have to 'remind' the patient that they are eating," he said.

"We ask everyone including Berlusconi to observe, to listen and not to get performance anxiety," he said, adding that the media magnate would be accompanied at all times by a medical worker specialised in Alzheimer's.

"We'll see if Berlusconi's presence creates some kind of close bond, if he is a reference for anyone. The guests do remember things, even if that seems absurd to people who do not know the illness," he said.

Berlusconi himself has said in interviews that he has a "big surprise" in store and has hinted that this could involve a deeper commitment to Alzheimer's sufferers.

"I think in the end I will stay a lot longer than I have to. I have a big surprise prepared. It took me just 10 days to learn the different cure methods that can be used," the 77-year-old told a radio show.

Emilio Fede, a former television anchor who has been convicted of procuring prostitutes for Berlusconi, has said his friend is unperturbed by the community service.

"Berlusconi is preparing carefully and is studying everything on Alzheimer's. He will do it well and with humanity," Fede said, adding that the service would be a tribute to Berlusconi's late mother, Rosa.

"She was a very important reference in his life and she always cared for elderly people," Fede said.

'Always helped people'

The sentence is seen as part of a slow-moving disintegration of Berlusconi as a political force, with his Forza Italia party divided by bickering and top allies indicted for mafia ties and corruption.

It was Berlusconi's first definitive criminal conviction and could herald more legal troubles ahead as he appeals a sentence for abuse of power and having sex with an underage prostitute.

He is also a defendant in a trial for bribing a former left-wing senator to undermine a rival party in power at the time.

The tax fraud case has highlighted delays in Italy's justice system since the investigation began back in 2001 with police raids on offices of his media empire Mediaset when he was prime minister.

He was first convicted in 2012 and lost his final appeal last year in a case that centred on fraudulent methods used to purchase film distribution rights in order to avoid paying taxes in Italy.

Berlusconi was sentenced to a year in prison, but a judge ruled he did not actually have to go to jail thanks to lenient sentencing guidelines in Italy for over-70s found guilty of non-violent crimes.

He was also spared house arrest and will only have to do community service for around 10 months -- as long as he respects a series of restrictions on his movements, including a nightly curfew.

Berlusconi, who has continually protested his innocence, has said he was happy with the community service.

"I'm actually pleased because in my life I have always helped people," he said.