ROME (Reuters) - Italy's opposition parties will try to defeat Prime Minister Silvio Berlusconi in parliament next week in a bid to force his resignation, a senior member of the center-left Democratic Party (PD) said on Wednesday.
"We think that next week will be a week in parliament where we try to force the situation if Berlusconi does not resign before," Enrico Letta, deputy general secretary of the party, told Reuters in an interview.
The PD, the largest opposition group in parliament, has called repeatedly for Berlusconi to resign and believes it may have a chance to defeat him because of the economic crisis.
Italy has felt the full force of the euro zone's debt problems which have sent its borrowing costs soaring and threatened to pitch it into a full-scale emergency.
On Tuesday, President Giorgio Napolitano issued a statement calling for reforms to be implemented immediately and saying he would explore the extent of support for reform among the broader social and political forces in Italy.
The statement appeared to indicate that he was ready to consider whether there was sufficient backing for a broadly based government of national unity if Berlusconi lost the backing of parliament.
Napolitano cannot dismiss Berlusconi while he still has a parliamentary majority, but as head of state he could appoint a leader to try to form a new government if the prime minister lost a confidence vote.
Opposition leaders met Napolitano on Wednesday to offer their support for a new government, led by a respected outsider, which could implement reforms and carry Italy through to elections in 2013.
"We are ready to assume our responsibilities and to support a new government with an agenda for reform and cutting the debt," said Letta.
"Of course it's absolutely indispensable to have a change of prime minister. Berlusconi is unfit to lead the country in this very difficult moment."
Berlusconi's approval ratings have plunged under the weight of an array of personal and financial scandals and the growing financial emergency.
His parliamentary majority has also suffered as a succession of deputies deserted the ruling PDL party, although his own supporters believe he still has the numbers to carry on.
One PDL lawmaker says their majority in the lower house is now four following the defection of a former loyalist on Tuesday.
Letta said that he believed that sufficient numbers of deputies on the right would be prepared to support a broad-based national unity government. He said the current coalition between Berlusconi's PDL and the Northern League, a regional pro-devolution party, could not continue.
"It's completely clear that no government with a small majority in parliament and no majority in the country, as all the polls demonstrate, can implement the reforms that Italy needs today," he said.
"It is absolutely necessary to change the situation and get a new government with wide support that can cut the debt and propose economic reforms.."
Editing By Barry Moody; and Robert Woodward