The alliance was announced on 31 July 2012 by the Secretary of the Democratic Party Pier Luigi Bersani and officially launched on 13 October, with the signature of a common political platform.[2]
By the terms of the agreement, each party in the coalition stood separately in the 2013 general election. However, all parties agreed to support a single candidate as Prime Minister. Bersani was elected as the coalition's leader and candidate for prime minister in the primary election held on 25 November and 2 December.[3][4][5]
In the election, the coalition gained a plurality in both houses of the Italian parliament, garnering 29.6% of the vote in the Chamber[6] and 31.6% of the vote in the Senate.[7] Although IBC had a solid majority of seats in the Chamber, it came up short of a majority in the Senate, thus leaving it unable to form a government on its own. Consequently, Bersani resigned from party leadership and the PD joined a grand coalition government, led by the PD's Enrico Letta.