In fact, Ingrao acknowledged the value of reforms on the "road to socialism", but he found the vision of Amendola and Longo to be devoid of a long-term strategic plan.

[3] During the Eleventh Party Congress (1966), Ingrao openly criticized Longo's refusal to allow public debate, which made him popular with a part of the participants.

However, it also led to the party leadership demonizing him as a factionalist; Ingrao later recalled that the leading cadres retained a cold posture in their seats and declined to shake his hand afterwards.

After PCI's then-secretary Achille Occhetto, in what was called the Svolta della Bolognina, decided to change the party's name, Ingrao became his main internal opponent.

After the 2004 European Parliament election in Italy, he abandoned the PDS and adhered as an independent to the more hardline successor to the old PCI, the Communist Refoundation Party.