[20][21] Civati and Pastorino were joined by Elly Schlein, a member of the European Parliament sitting in the Socialists and Democrats' Group,[22] and two more deputies, Andrea Maestri and Beatrice Brignone.

[23][24][25] At Possible's launch, Civati explained that it was intended to "have minimum bureaucracy, and membership will be light, participatory, horizontal"[26] and aimed at unifying all the parties, groups and individuals to the left of the PD, including Sergio Cofferati, Stefano Fassina, Nichi Vendola's Left Ecology Freedom (SEL), Maurizio Landini's Social Coalition, the Greens and other environmentalists, etc., in a single party, with a potential support around 10% of the vote.

[27] Also representatives of the Italian Radicals, Green Italia, the Communist Refoundation Party, Free Alternative (AL) and Italy Work in Progress (the latter two splinter groups from the Five Star Movement, M5S) showed up at Possible's first convention in Rome.

[36] Consequently, Possible joined forces with AL, which was active also at the grassroots' level, and formed a joint sub-group within the Mixed Group of the Chamber.

[43][44][45] In December 2017, Possible was a founding member, along with the MDP and SI, of Free and Equal (LeU), the left-wing joint list for the 2018 general election, which chose the President of the Senate and former anti-Mafia prosecutor Pietro Grasso as its leader and candidate for Prime Minister.

[50][51] In the run-up of the 2022 general election, the party joined the Greens and Left Alliance (AVS), earlier formed by SI and EV.