The RnP was composed of the Italian Democratic Socialists (SDI; a social-democratic party led by Enrico Boselli and Roberto Villetti), the Italian Radicals (RI; a liberal-libertarian party led by Marco Pannella and Emma Bonino) and some independent members gathered in the Association for the Rose in the Fist (including Lanfranco Turci, Salvatore Buglio, and Biagio De Giovanni).

The federation was constituted in September 2005, during a convention held in Fiuggi, based on the political principles of José Luis Rodríguez Zapatero (excluding foreign policy, where the Radicals have an Atlanticist, pro-American stance), Tony Blair and Loris Fortuna.

There was also the so-called "third component", composed mainly by former Democrats of the Left, such as Lanfranco Turci, Salvatore Buglio and Biagio De Giovanni, gathered in the Association for the Rose in the Fist.

[2] The alliance was disbanded in December 2007, upon which the SDI merged with the Association for the Rose in the Fist and other minor movements to form the current-day Italian Socialist Party.

The table below shows how the two parties were not able to secure the favour of their usual voters, so that the Rose in the Fist scored less than Radicals alone in the North and the Socialists alone in the South.