Former Prime Minister Silvio Berlusconi threatened to withdraw his party’s support from his successor, Mario Monti, leaving the government teetering and sending Italian bonds tumbling.

Monti today postponed a cabinet meeting at his office in central Rome and rushed to the nearby Senate to attend a confidence vote after Berlusconi allies announced a mass abstention. While the economic stimulus bill survived, Monti faces another confidence vote in the lower house today and the remaining months of his tenure were placed in doubt.