She stood by him when he phoned adult sex lines. She remained by his side after he employed a topless model in his Cabinet. She even forgave the relentless flirting with women a third his age. Now, however, after nearly 20 years of marriage, Veronica Lario, the long-suffering wife of Silvio Berlusconi, the Italian Prime Minister, has had enough.

Ms Lario, 52, lamented yesterday at having “been forced to take this step”, but said that she wanted an amicable agreement, telling an Italian newspaper: “I want to bring down the curtain but I want to do it properly and without any fuss.”

Ms Lario, who met Mr Berlusconi nearly 30 years ago, attacked last week his plans to field young attractive showgirls in the European Parliament elections next month as “shameless rubbish to entertain the Emperor”.

Her fury was fuelled by the revelation that her husband had attended the 18th birthday party of Noemi Letizia, a friend’s daughter, and had given her a diamond and gold necklace. Ms Lario said that he had never attended his own children’s 18th birthday parties.

In January 2007 Ms Lario published an open letter in La Repubblica demanding a public apology from her husband after he flirted with showgirls at a television awards ceremony and praised the beauty of Mara Carfagna, a former topless model who is now his Minister for Equal Opportunities. This came a year after he phoned nine adult sex lines to conduct an impromptu pre-election opinion poll.

Now it appears that Ms Lario has finally reached her limit. “I am going to ask for a divorce,” she said yesterday. “I cannot stay with a man who surrounds himself with minors.”

She came to the decision even after being told by her lawyer: “You must understand that it will not be easy and you will have to endure heavy attacks.” Mr Berlusconi’s media empire controls much of the news and entertainment in Italy.

The Italian Prime Minister met Ms Lario — whose real name is Miriam Bartolini — in 1980 when she was appearing topless in a play in Milan called The Magnificent Cuckold.

At the time Mr Berlusconi was married to his first wife, Carla Elvira Dall’Oglio, with whom he has two children, Marina and Pier Silvio. Both are senior executives in his empire.

His first child by Ms Lario, Barbara, 24, was born while he was still married to his first wife, whom he divorced in 1985. He then had two more children with Ms Lario, Eleonora, 22, and Luigi, 19, before the couple married in 1990.

Ms Lario said yesterday of her divorce: “I want to do this like an ordinary, upright person. I don’t want a fight.” Mr Berlusconi said in a statement: “This is a painful personal affair, and is part of my private life. Obviously, I won’t be talking about it.”

Mr Berlusconi reportedly wants to leave half of his empire to his older childen and the other half to the younger ones. Ms Lario, however, is said to be pressing for 20 per cent of the estate to be left to each child, giving her offspring the majority stake.

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