On 24 January 2008 Prime Minister of Italy Romano Prodi lost a vote of confidence in the Senate by a vote of 161 to 156 votes, causing the downfall of his government. Prodi's resignation led President Giorgio Napolitano to request the president of the Senate, Franco Marini, to assess the possibility to form a caretaker government. The other possibility would have been to call for early elections immediately. Marini acknowledged impossibility to form an interim government due to the unavailability of the centre-right parties, and early elections were scheduled for 13 April and 14 April 2008.
Prodi had at the time been in office for 20 months, after winning the April 2006 general election. In February 2007, the Prime Minister handed in his resignation, only to be asked to remain by the President, and winning a vote of confidence in the Parliament.
Prodi had built his government around a coalition called The Union, which consisted of a large number of smaller parties. This situation was in turn the result of an electoral system of proportional representation, due to legislation passed by Berlusconi three months before he lost power. It was when the leader of one of these lesser parties, Justice Minister Clemente Mastella of the Union of Democrats for Europe (UDEUR), came under investigation for corruption that the coalition started to break up. When the media reported an extensive corruption investigation involving Mastella and his wife – an UDEUR politician in Campania – Mastella resigned.
After first promising to support the government, he later retracted this support, and his party followed, in part also due to pressure from the Vatican, for which the government's proposed laws in regards to registered partnerships of same-sex couples, and other liberal reforms were objectionable.