Silvio Berlusconi, Italy’s former prime minister and the leader of the center-right People of Freedom (PDL) party, the largest in parliament, has threatened to bring down the Mario Monti government.

Berlusconi said the government was leading Italy into a recession and added that his PDL party would decide if it would stop supporting the government or not. The move is likely to trigger early polls, the BBC reported.

Berlusconi, forced to step down in 2011, made the statement shortly after he was found guilty of tax fraud and sentenced to four years in prison. The sentence was later reduced to one year due to a 2006 amnesty law aimed at reducing prison overcrowding, according to the BBC. The ex-premier plans to appeal it.

Berlusconi accused the Monti government of "fiscal extortion". His speech came as thousands of protesters marched through Rome in a protest against the Monti government-launched austerity measures.

A Milan court on Friday convicted Berlusconi, 76, of tax fraud in connection with the media magnate's Mediaset television company. The Mediaset case has been one of the most high-profile and controversial trials involving Berlusconi’s business activity.

According to the prosecution, Mediaset was involved in a scheme to acquire the rights to broadcast movies on Berlusconi's private television networks via shell companies, evading tax payments through false accounting and financial reports. Berlusconi denounced the judges as biased and politicized.

The court ruled that Berlusconi, together with other defendants in the case, is to pay Italian tax services 10 million euros and imposed on the tycoon a five-year ban on running for political office.

Both the ban and the prison term will come into force if the sentence is upheld by a higher court. Berlusconi’s lawyers said they will lodge an appeal by November 10.

Berlusconi said on Saturday he intended to stay in politics.

“I feel obliged to stay in the political field and to reform the justice system so that what happened to me doesn't happen to other citizens,” Berlusconi told Italy’s Canale 5, the flagship of his media empire.

The statement came as a surprise as on Wednesday Berlusconi said he would not run for prime minister next year.