Not for the first time, the Italian centre-right opposition leader, Mr Silvio Berlusconi, has sent shock waves through politics, threatening to withdraw his support for constitutional reforms.
Opposition and government parties are now headed for a desperate last-minute effort to save the package before a crucial vote on Tuesday. As the package includes constitutional, institutional and electoral reforms, a two-thirds parliamentary majority rather than a simple majority is required.
This latest political crisis might have passed unnoticed, had it not been for the ill-timed speculation by the Lower House Speaker, Mr Luciano Violante, that if the reform process broke down, then early elections were the most likely outcome.
That comment inevitably raised the familiar spectre of unstable, revolving-door style government that has seen 54 executives come and go since 1946, a spectre many hoped had been partially exorcised by the 55th post-war government of the centre-left Prime Minister, Mr Romano Prodi, in power since May 1996.
Ironically, the main aim of the reforms package is to ensure government stability and durability.
In reality, Mr Violante's comments may have been too alarmist. If the reforms package fails, then the biggest casualty would not be the Prodi government, which has never tied its fate in any specific way to the package, but the long-awaited reform process itself.
If the package fails, then the men facing the biggest headaches will be the two main protagonists in the bicameral, all-party parliamentary commission which delivered the package - Mr Berlusconi and Mr Massimo d'Alema, leader of Democratic Left (PDS), the former Communist Party and the largest single component in the Prodi government coalition.
Both men will face criticism from within their own coalitions as to why they formed an unlikely partnership to force through a compromise package that was widely held to be unsatisfactory.
Mr d'Alema is pointing the finger at Mr Berlusconi, arguing that the Forza Italia leader has gone back on his word. Mr d'Alema may have a point, since Mr Berlusconi seems to have radically changed his mind since last June. Then he spoke of his pride at having contributed to an agreement that "had proved difficult but was useful for the country".
Last November, on the conclusion of the commission, Mr Berlusconi seemed even more enthusiastic, saying: "This is a positive outcome. Remember that it was us of the Freedom Poll (centreright opposition) who wanted these reforms at a time when the government majority didn't want to know about them".
For months Mr Berlusconi has appeared about to withdraw his support unless the package includes radical reform of the judiciary. Many commentators believe Mr Berlusconi's enthusiasm for this reform may not be unrelated to the fact that he is facing a variety of corruption charges related to his Fininvest empire.
Furthermore, a partial centreright success in last weekend's first round of local elections may have encouraged the TV tycoon to flex his muscles now rather than later. Given that his main right-wing ally, Alleanza Nazionale leader, Mr Gianfranco Fini, on Wednesday refused to condone the threat to ditch the reforms, it could be that Mr Berlusconi has got his timing wrong.