A series of official events commemorated the occasion with a flypast of jets trailing the colors of the Italian flag, a 21 gun salute before a statue of national hero Giuseppe Garibaldi and a gala performance of Verdi’s opera Nabucco in Rome.

But the decision by Prime Minister Silvio Berlusconi’s coalition allies in the Northern League to boycott the holiday highlighted a sense the celebrations concealed deeper tensions, exacerbated by low economic growth and creaking public finances.

“We will only succeed on one condition, which is that there is once again a strong national bond uniting us, which is not eroded and dissolved by blind partisanship,” President Giorgio Napolitano said in a speech to a special sitting of parliament.

Italy is going through a particularly acrimonious phase in its political life, with Berlusconi facing opposition calls to resign over a scandal in which he has been charged with paying for sex with a minor.

The holiday on March 17 — the date on which Vittorio Emanuele II was declared King of Italy by the newly constituted national parliament in 1861 — was only approved last month and many in the Northern League have rejected it.

The League, formed in the wake of the “Bribesville” corruption scandals which destroyed the old Italian political order in the 1990s, remains suspicious of central government in Rome and only a handful of League members were in parliament to hear Napolitano speak.

The party, whose support is vital to the survival of Berlusconi’s government, is officially committed to the goal of a separate region it calls “Padania,” undermining the whole notion of a single unified state.

Even if many League members acknowledge there is no immediate prospect of devolution, the party wants reforms that would give individual regions far greater autonomy over their financial affairs.

The League says the rich and hardworking northern regions have been held back by an unproductive and frequently corrupt south, where organized crime and a bloated public sector overshadow economic life.

“Italy is really two different countries,” said Mario Borghezio, a hard-line Northern League member of the European Parliament.

Economic data support his argument, with jobless rates in the south running at over 13 percent against less than 6 percent in the north, or per capita GDP at around 17,000 euros in the south against 30,000 in the richest region in the northwest.

The problem is a deep-rooted one, going back well before the nationalist movement led by Garibaldi overthrew the old Kingdom of Naples to usher in the new era in 1861. Napolitano said it was “at the center of our concerns and national responsibility.”

But the Northern League itself remains deeply skeptical it can be solved within the current state structure, striking at the heart of the message of national unity the March 17 holiday was meant to deliver.

“The centralized state is a judicial prison,” Borghezio told Reuters. “It’s something I want us to break away from.”