Opposition lawmakers on Friday demanded that Berlusconi address Parliament to explain the impact of his decision to oust Gianfranco Fini from the People of Liberty Party that he co-founded with Berlusconi.

The premier met with another ally, the head of the Northern League, Umberto Bossi, whose support is essential to a stable government because his party gives Berlusconi's movement the margin it needs to govern comfortably.

Asked if the split with Fini would force early elections, Bossi raised his middle finger to reporters.

Berlusconi and Fini, whose alliance dates to Berlusconi's transition to politics in the early 1990s, have been fighting for months on just about every policy matter, from immigration to proposed restrictions on wiretaps. But observers see it as more of a power struggle than ideological differences.

Berlusconi's People of Liberty Party issued a document late Thursday accusing Fini of creating a "party within a party" and fomenting "intolerable" opposition within party ranks.

Fini's allies in the chamber announced they were pulling out of Berlusconi's movement, but Fini is resisting pressure to step down as house speaker, a position elected by lawmakers not appointed by the premier.

Fini was expected to make a statement later Friday. Fini formerly led the National Alliance, which was absorbed into the People of Liberty Party movement. Still, Fini supporters retain autonomy in parliament, where they have 33 seats in the lower house and 14 in the upper house, or Senate.

Berlusconi's movement controls 342 seats in the 630-member lower house, and 175 seats of the 322-seat Senate.

Berlusconi insisted Thursday the government was not at risk and that he has the support of the majority of Italians.

Despite the rift, the lower house easily passed controversial austerity measures on Thursday aimed at reducing Italy's deficit.

Fabio Fois, an analyst at Barclay's Capital, said the measure's passage could signal that Fini does not intend to discredit Berlusconi's government, but instead is seeking "to apply some political pressure." Berlusconi's current government took office in May 2008 with a five-year mandate. Confidence in his government has been slipping, coming in at 33 percent in July from 49 percent at the beginning of the government and a peak of 54 percent in September 2008. The poll by IPR marketing has a margin of error of plus or minus 4 percentage points.