Resignation Weakens Italy’s Government

A new element of instability shook Italy’s government Thursday as the justice minister, resigning over a corruption investigation, withdrew his small party from the already fragile center-left ruling coalition.

The minister, Clemente Mastella, did not seem intent on immediately bringing down the government of Prime Minister Romano Prodi, who now holds only a one-seat majority in the Senate. Mr. Mastella said he would use his crucial three seats in that body largely to support Mr. Prodi, even if outside the coalition.

But amid much tension in the nearly two-year government, political experts said Mr. Mastella’s withdrawal loosened a loyalty to Mr. Prodi which was never absolute anyway — signaling that a full-bore crisis may not be far off.

“We are now in a real situation of pre-crisis for this government,” said Ignazio La Russa, leader of the opposition National Alliance party, echoing the sentiment of many experts and even many inside the government.

Underscoring the unsteady state of play, Mr. Mastella, 60, a maverick politician who leads a small Catholic party that has also supported the center-right, said he would pledge his votes only case-by-case.

“We will be demanding, not like before when we accepted compromises,” he told reporters in the southern city of Benevento.

The latest test for Mr. Prodi’s government, which has weathered one difficulty after another, began Wednesday when Mr. Mastella’s wife, Sandra Lonardo, a politician in the southern Campania region, was placed under house arrest as part of a corruption investigation into a local health care system that also targeted several members of his party.

Italian media reports said that Mr. Mastella himself was also under investigation for exerting influence in political appointments. He declared himself and his wife innocent and the charges politically motivated.

The resignation comes at a sensitive moment, as Mr. Prodi’s fractured nine-party coalition is in difficult negotiations among themselves and the opposition over a new electoral law. Several proposals — including one in a referendum given court approval this week — could significantly lessen the influence of small parties like Mr. Mastella’s, another possible source of conflict.

Mr. Prodi, addressing the lower house of parliament, said he would temporarily serve as justice minister, a move approved by President Giorgio Napoletano earlier in the day. But Mr. Prodi made clear how crucial Mr. Mastella’s support is for his government’s survival, expressing his “full solidarity” with Mr. Mastella and saying he could return to his post when he was cleared of the charges.

Mr. Prodi had also asked Mr. Mastella to reconsider when he originally tendered his resignation on Wednesday after his wife was put under house arrest. Mr. Mastella said on Thursday he would step down so he could face the charges “like a common citizen before the law.” He said: “I don’t want to give the idea that that as a minister I could get a lenient verdict.”

Mr. Mastella has been a particularly contentious member of Mr. Prodi’s government. He served as a minister under the former prime minister Silvio Berlusconi and had threatened to abandon Mr. Prodi on several key votes.