Silvio Berlusconi, the Italian Prime Minister, complains that he is a victim of defamation. He has rounded on La Repubblica after the newspaper challenged him to explain his relationship with an 18-year-old aspiring model, Noemi Letizia, who addresses him as “Daddy”. According to Mr Berlusconi, this is a left-wing plot to undermine his authority.

Mr Berlusconi’s complaint is blustering nonsense. He has invited derision by his promotion as candidates in the European elections of young women whose personal glamour exceeds their political knowledge. This latest stunt has provoked his longsuffering wife to demand a divorce. The questions posed by La Repubblica — about Mr Berlusconi’s involvement in the selection of candidates, and whether he has promised to assist Ms Letizia in a political or showbusiness career — are not an intrusion into private life. They relate to Mr Berlusconi’s public roles as politician and media magnate.

Mr Berlusconi’s convoluted political dealings are muddied further by his media dominance. He controls three national television channels. His campaign against La Repubblica looks ominously like an attempt to cow dissent rather than protect a private reputation. It is especially tawdry that he has used his media position to criticise his wife, insinuating that she is mentally unstable.

These are the actions of a wealthy and powerful man who treats politics and the media as fiefdoms. Mr Berlusconi has little apparent sense of the division between private interest and public duty. His newspaper critics are performing a public service for a badly governed populace.