Rome, Italy (CNN) -- A former ally-turned-rival of Silvio Berlusconi called on the Italian prime minister to resign Sunday, threatening to prompt a government crisis if he does not.
"He must tender his resignation," said Gianfranco Fini, "And start a phase where the political agenda is discussed, the program is discussed, and the nature of the coalition is verified."
If the prime minister doesn't step down, Fini warned that ministers and undersecretaries loyal to him would resign, sparking a political crisis.
Berlusconi expelled Fini from his People of Freedom (PDL) party this summer, and about 40 lawmakers followed Fini out of the party.
Fini founded a new party, Future and Liberty, and was speaking Sunday at a rally for the party in Umbria, northern Italy.
Berlusconi survived a vote of confidence at the end of September, but Fini's supporters backed the prime minister at that time. If they turn against him, Berlusconi might lack enough votes to survive another confidence vote.
Italian media reported Sunday that Berlusconi said that he would not resign.
Political analyst James Walston told CNN there was an element of bluster in Fini's speech Sunday.
"Fini is not completely closing the door to Berlusconi," Walston said. "He was strong against him and was clearly provoking him, but Italian politics is strange and up till now Fini has been playing a double game, because he doesn't want to go to elections yet."
Italian President Giorgio Napolitano, who has the authority to dissolve parliament, has said he opposes new elections because it would create instability at a time of economic crisis.
In his speech, Fini accused Berlusconi of a lack of attention to the economic crisis and structural reforms that Italy needs.
Berlusconi faces a difficult economic picture as he looks ahead to the rest of his term, which expires in 2013.
Italian unemployment is running at 8.5 percent, the highest level since 2003, according to the Italian statistical office, and public debt is 120 percent of the country's gross domestic product, the Bank of Italy says.