Italy ex-PM Berlusconi threatens to topple Monti government
Italian ex-PM Silvio Berlusconi has threatened to bring down the government of technocrats led by Mario Monti.
Mr Berlusconi said the cabinet was leading Italy into a "spiral of recession" and that his centre-right PDL party would decide in the coming days whether it would end its support.
It is the largest party in parliament and the move could trigger early polls.
Mr Berlusconi was forced to step down last year. His comments come a day after he was found guilty of tax fraud.
He is expected to appeal against the four-year-jail sentence - reduced to one - on charges of inflating the price of distribution rights bought by his Mediaset group to avoid paying taxes.
Mr Berlusconi was speaking as thousands of protesters marched through Rome in a demonstration against austerity measures launched by the Monti government.
The former prime minister accused the Monti government of "fiscal extortion".
"We have to recognise the fact that the initiative of this government is a continuation of a spiral of recession for our economy," Mr Berlusconi said.
"Together with my collaborators we will decide in the next few days whether it is better to immediately withdraw our confidence in this government or keep it, given the elections that are scheduled."
The last election was held in 2008 and the next is due in 2013.
Mr Monti was appointed last November, when Italy's credit rating was affected by the eurozone debt crisis.
His government has since pushed through tax rises, spending cuts and an overhaul of the pension system.
The BBC's David Willey in Rome says Mr Berlusconi, a combative politician, is unlikely to lie down and was puffing with anger as he was addressing journalists.
Earlier on Saturday, Mr Berlusconi said that despite his conviction he felt "obliged" to stay in politics.
He said he wanted to "reform the justice system so that what happened to me doesn't happen to other citizens".
"Ours is not a democracy but a dictatorship of the judges," he told TG5, one of the TV channels owned by Mediaset.
However he confirmed he did not want to stand for prime minister.
Mr Berlusconi has faced a number of trials. He has in the past either been cleared, or cases have run beyond the judicial time limit.
In 1997 he received a suspended sentence for false book-keeping but that conviction was reversed on appeal.
This week's jail term, and a five-year ban from holding office, will only take effect if it is upheld by a higher court.
In February a court threw out a corruption case against him after the statute of limitations had expired.
He is also currently on trial charged with paying for sex with an underage girl and trying to cover it up. He denies any wrongdoing.