Perhaps, when the architect Daniel Libeskind produced his grand plans for an art museum and office tower designed to inspire civic pride in the heart of Milan, he should not have been surprised when Italy's gaffe-prone Prime Minister, Silvio Berlusconi, said the bent structure emanated a "sense of impotence" because it is not manly enough.

But Libeskind, an American born in Poland, was so outraged that he accused Mr Berlusconi of being a xenophobe who proffers "repugnant" politics, according to the The Art Newspaper. The war of words culminated in the premier's latest threat this month to withdraw planning permission for the museum.

The spat began when Mr Berlusconi made an off-the-cuff remark about Libeskind's design for the tower, part of the Fiera Milano site. The skyscraper, intended to be situated between buildings designed by the British architect Zaha Hadid and her Japanese colleague Arata Isozaki, curves dramatically, a feature …