A right-wing party allied with Italian Prime Minister Silvio Berlusconi voted Thursday against a government decree to ease a garbage crisis in Naples but the vote was later annulled due to a technicality.

Lower house of parliament speaker Gianfranco Fini said the vote — in which the Northern League voted along with the centre-left opposition against an amendment — was annulled because of a "material mistake".

"The amendment concerned a part of the decree which had already been deleted and was submitted for a vote by mistake," Fini said. "This was a material mistake."

The amendment on the construction in Naples of a state-of-the-art incinerator had been proposed by the centrist UDC party and was designed to put a cap on the temporary stockpiling of untreated waste.

"We're talking about minor differences inside the governing parties," commented Italo Bocchino of Berlusconi's People's Party for Freedom.

The openly xenophobic and anti-immigration Northern League, led by firebrand Umberto Bossi, made an unexpectedly strong showing in parliamentary elections in April, winning eight percent of the votes.

Berlusconi has pledged to solve the longstanding garbage crisis in the Naples region within 30 months.