Pier Luigi Bersani, head of the Democratic Party, said the experience of past administrations had shown that Italians were prepared to accept big sacrifices as long as they were justified and properly explained.

"Even if there was something of a 'honeymoon effect' when the Monti government appeared, the very wide public support you saw wasn't because people expected sweets and presents," he told Reuters. "People are looking for fairness and truth. If you have fairness and truth, you'll have people's confidence."

Monti was appointed last week at the head of a "technical government" of academics, civil servants and administrators to succeed Silvio Berlusconi after the scandal-plagued prime minister lost his parliamentary majority.

With images still vivid of riots in Athens and Rome in recent months, financial markets have been watching anxiously to see whether the new technocrat governments in Italy and Greece have sufficient public support to pass painful reforms.

The former European Commissioner has warned Italy to expect sacrifices on the way to restoring public finances and regaining lost international credibility in the face of a mounting crisis which has sent borrowing costs soaring to untenable levels. [nL5E7LR1WL]

But he has also made "fairness" one of the three priorities, along with budget rigor and moves to encourage growth in Italy's sluggish economy.

"I see that the problems are hard but I don't see the problem in winning consensus as long as the measures Monti is talking about are equitable and give the feeling that this is a shared sacrifice," Bersani said.

SUPPORT

Raising the effective pension age, loosening job protection measures and new taxes are all under discussion and Monti will need to retain the support of a fractious parliament to remain in power until the next scheduled election in 2013.

Bersani dismissed fears that the center-left may balk at some of the measures, most demanded by Italy's European partners, and said they were generally seen as necessary.

"We are ready to back the basic conditions, balancing the budget, growth but I think that in the next few weeks we'll see that Italy, as it has on other occasions, is in a position to meet these conditions on its own criteria."

He said Monti's appointment had visibly changed the climate of Italian politics from the bitter divisions of just two weeks ago and led to an improvement in its international image.

"I think it's obvious that with this government we are regaining our place in Europe," he said, a day before Monti meets German Chancellor Angela Merkel and French President Nicolas Sarkozy in Strasbourg.

According to a survey by pollsters Piepoli in the La Stampa daily on Wednesday, 73 percent of Italians have confidence in the new government, compared with the 28 percent support for the Berlusconi government registered in its last week in power.

The appointment of a non-elected administration under pressure from financial markets echoes what has happened in Greece, where former European Central Bank vice president Lucas Papademos now heads the government.

There has been widespread speculation that his government could fall early next year with Berlusconi's center-right bloc expressing only conditional support and newspapers close to the former premier sniping at Monti.

However, Bersani said parliament would be held to account for any obstruction and he expected a greater sense of responsibility in the post-Berlusconi era.

"I think parliament is going to feel more responsibility, more part of the process. It'll have to justify itself to the public if it blocks this government," he said.

(Reporting By James Mackenzie; Editing by Janet Lawrence)