* Prosecutors allege "system of organised prostitution"
* Want 5 years for abuse of office, year for sex with minor
* Call for permanent ban on public office
* Berlusconi legal woes add to tensions facing new PM Letta
Italian prosecutors on Monday called for a six-year jail sentence and a lifetime ban on holding public office for former Prime Minister Silvio Berlusconi, charged with abuse of office and paying for sex with a minor.
The 76-year-old billionaire media tycoon and centre-right senator is accused of paying for sex with Karima El Mahroug, better known by her stage name 'Ruby the Heartstealer', when she was under 18, during the now notorious "bunga bunga" parties at his villa at Arcore near Milan in 2010.
However, prosecutors considered by far the more serious charge was that he abused the powers of his office during a separate incident by arranging for her to be released from police custody where she was being held on theft charges.
They requested 5 years imprisonment for that and a year for paying for sex with a minor. The verdict is expected on June 24.
"At Arcore there was a system of organised prostitution aimed at the satisfaction of the sexual pleasure of Silvio Berlusconi," Milan chief prosecutor Ilda Boccassini said in a more than six-hour closing argument.
"There is no doubt that Ruby had sex with the defendant, from whom she received benefits," she said.
Berlusconi has vigorously denied the accusations. El Mahroug, who staged a dramatic protest outside the Milan court last month, has always denied being a prostitute or having had sex with Berlusconi.
The sentencing request adds to a mass of legal problems facing Berlusconi, who last week lost an appeal against a four-year sentence for tax fraud in connection with his Mediaset broadcasting empire. Berlusconi will now launch a second and final appeal.
No final verdict will be enforced until the appeals process, which can last for years, is exhausted but Berlusconi's legal sagas have created growing tension within the coalition government of Prime Minister Enrico Letta.
Berlusconi mounted a fierce attack on prosecutors over the weekend at a stormy rally in the northern city of Brescia that was attended by centre-right members of the government including Interior Minister Angelino Alfano.
Letta's own centre-left Democratic Party (PD) sharply criticised Alfano's presence at the rally, which it took as an endorsement of Berlusconi's comments and the prime minister warned his coalition partners that there could be no repeat if the government was to survive.
Berlusconi's campaign continued on Sunday with a lavish two-hour special on his own Canale 5 channel presenting his version of the "bunga bunga" evenings where prosecutors allege that sex parties involving a string of young women took place.
The programme showed El Mahroug admitting that she had lied about certain aspects of her life to investigators but flatly denying any sexual relationship with Berlusconi and complaining at media representations of her as a prostitute.
It filmed the dining room and theatre at Berlusconi's palatial villa near Milan and presented an array of witnesses who said the evenings there were convivial parties where he entertained guests by singing and telling stories.