As if he did not have enough on his plate — more sex scandal allegations, tensions with the Vatican and within his coalition, the Italian economy — Silvio Berlusconi has another hot potato this autumn: how to celebrate 150 years of Italian national unity.

The anniversary does not fall until March 2011, marking the declaration of Italian unity in 1861 after the Risorgimento, the nationalist armed struggle led by Giuseppe Garibaldi. But President Napolitano has expressed concern that the celebrations will not be ready in time after Mr Berlusconi announced that plans drawn up by the previous centre-left government of Romano Prodi were being “rethought”.

Italy, as Corriere della Sera pointed out recently, is probably the European state with the least developed sense of national identity. “Italia”, Metternich observed in the 19th century, was a “geographical expression”, with the nation forged out of a patchwork of mutually hostile duchies, kingdoms and city states.

Italians today tend to be nationalistic when abroad, or when supporting the Azzurri, the national football team. But at home their deepest loyalty is often still to their region or even local community. Arguably 1861 is not even the real unification date, since papal Rome did not fall until 1870.

The real fly in the ointment is the separatist-minded Northern League, part of Mr Berlusconi’s coalition Government. Umberto Bossi, its leader, founded the League as a vehicle for regional autonomy in Northern Italy, playing on northern resentment of the “shiftless and subsidised” South, or Mezzogiorno, propped up by “the thieving Government in Rome”.

The League veers between demands for devolution or federalism — its current position — and outright separatism. It has created an imaginary state in Northern Italy called Padania, with its own green-shirted militia and national anthem - Verdi’s stirring chorus Va Pensiero from the opera Nabucco, instead of the national anthem by Goffredo Mameli, a Risorgimento poet and hero. In what is meant to be a mystical “Padanian” rite Mr Bossi will on Friday begin a three-day journey from the mountains of Piedmont to Venice carring a phial of “sacred water from the Po” — as he has since 1996.

“Unity of Italy — what is there to celebrate?” ran a recent headline in La Padania, the League’s newspaper, adding that the unification of Italy was “an act against nature and history”. For Mario Borghezio, a Northern League MEP, plans for “Pharaonic celebrations” to mark the 150th anniversary are a waste of public money. “People have other priorities,” said Roberto Cota, head of the Northern League faction in the Italian Parliament.

Mr Berlusconi agrees that the Prodi 2011 plans — costed at about €350 million — look extravagant in the light of recession and scarce resources. They include 11 big infastructure projects and nearly 400 nationwide cultural events such as music, arts, film and dance festivals. Building projects include a Palace of Cinema in Venice, a music auditorium in Florence, an airport at Perugia, an archeological museum in Reggo Calabria, the restoration of the San Carlo opera house in Naples and theatres at Pescara and Turin, and "Italian unity museums" at Potenza, Caserta and Reggio Emilia.

It remains unclear how many of these will survive. Sandro Bondi, the Culture Minister, maintains that the slimmed down events will still celebrate unity as well as regional pride and identity, but "in a federal spirit — ours is a country with many stories".

The Berlusconi Government's counter proposals include television documentaries, the promotion of local dialects, and a plan to rename Piazza Venezia, the main square of Rome, "Piazza dell' Unita d'Italia". Even this last has run into local opposition however. "Let's create Italian unity first," Massimiliano Fuksas, the architect, said. "Then we can start renaming piazzas".

Times Recommends

• Lessons in revolution, via YouTube
• A deadly game of wits on the roads of blood
• Florida braces for Kennedy charm attack