Gianfranco Fini, the speaker of the lower house of Italy's parliament and now the loudest opponent to Prime Minister Silvio Berlusconi, took another swing at the embattled prime minister Sunday, announcing that key followers will leave the government on Monday.

Italian Prime Minister Silvio Berlusconi (R) and Italy's lower house speaker Gianfranco Fini talk as they attend the celebration of the Italian Army's anniversary in Rome November 4, 2010. [Xinhua]

Fini, who a week earlier called on Berlusconi to resign, further forced the issue Sunday when he announced that European Affairs Minister Andrea Ronchi, a deputy minister and two undersecretaries would present their letters of resignation to Berlusconi on Monday, after the prime minister's return from the Group of 20 summit in South Korea.

Though the four resignations alone will not cause the government to fall, it adds to the political instability in Italy.

Italian media reported from South Korea that Berlusconi on Saturday said he would call a do-or-die confidence vote in both chambers of parliament, though he would wait until the country's 2011 budget is passed -- probably in mid-December.

It appears that even without the support of Fini and his allies that Berlusconi would retain a slim majority in the Senate, but not in the lower house.

If the confidence vote is held and Berlusconi loses, it would cloud the political landscape, with several scenarios possible, including early elections, the possibility that Berlusconi could try to cobble together a new government majority, or the appointment of a non-partisan technical government that would oversee an electoral overhaul ahead of new elections later in the year.

Berlusconi said Sunday he believes he will retain power despite the crisis, telling followers he retains the support of 60 percent of Italians.

But recent polls contradict him, showing support levels in the range of 30 to 35 percent, its lowest level since he returned to power in 2008.