The direction of PSI was dissolved, transferring its powers to some managers living abroad and in contact with the socialist secretary Olindo Vernocchi from Rome, while sections ceased to communicate with each other.

Leaders decided to keep the party alive «with its physiognomy, tactics and programme», recommending to cease every trending activity and to act «in favour of comrades affected by the fascist terror».

[7] An anti-merger movement was formed in Milan on 14 January 1923 within the National Committee of Socialist Defence (Comitato Nazionale di Difesa Socialista), which occupied the headquarter of Avanti!

[5] This dialectic, derived from the traditional libertarian soul of the party, was completely inconclusive and inadequate to face with determination the contemporary political situation, characterized by freedom-destroying provisions that confirmed the establishment of the fascist regime with the end of syndical freedoms, the illegality of strike proclamation and the suppression of elective communal councils, replaced by mayors appointed by the government.

The purpose of CAI was the organization of Italian antifascist forces in order to reorganize the anti-fascist movement abroad avoiding to repeat the old divisions existing in Italy before the establishment of the regime.

[12] Due to the divisions among the members, CAI showed poor accomplishing skills since its first actions: it obtained success defending the emigrates in France, urging the intervention of LIDU in the assistance to the victims (including communists) of police provisions.

[13] Moreover, this circumstance fuelled the left opposition within the PSI, which had its strengths in the sections of Vienne and Paris, where a third formation was formed in favour of the entry of socialists into the Antifascist Proletarian Committees (Comitati Proletari Antifascisti), organized by PCd'I.

The area led by Angelica Balabanoff tried to rebut the fusionist moves of Nenni with an expedient: a political line change and a merger with socialist reformist PSULI had to be confirmed by a formal congress held in Italy, not by an emigrated representation of PSI.

Among them there was the Grand Orient of Paris: according to a confidential communication of the Italian Ministry of the Interior, it deliberated to push on socialist leaders in order to achieve the fusion of the two parties «generally not belonging to Masonry», of whose support «they need every day for work purposes and political protection».

The controversy within PSI became unstoppable and spread also outside the French borders, in particular among the Italian Socialist Federation of Switzerland which was publishing in Zurich L'Avvenire dei lavoratori ("The Future of Workers"), supporter at the time of pro-merger positions.

[14] Another cause of conflicts within the party was the role of the Concentration: Balabanoff accused reformists (who were holding the power inside the association as well as the LSI funds) to keep it inert.

[14] During a reunion, fusionist ascertained that the direction did not want to revoke the expulsion measures (rejecting also their motion) and they decided to not participate to the Convention held in the local Bourse du Travail.

Moreover, the party decided to leave the reformist General Confederation of Labour led by Bruno Buozzi, who wanted to join the Sindacati Rossi ("Red Unions") formed by the communists.

[18] Nenni, along with Giuseppe Saragat, performed an operation intended to liquidate reformism and maximalism in favour of the establishment of a «rigorously Marxist and democratic socialism, adopting the class struggle as instrument and the liberation of humanity from every economical and political serfdom as purpose».

In a climate of attacks from PCd'I when it was carrying out the political line of “social fascism”, the third General Convention of the Italian (Maximalist) Socialist Party was hold abroad in Lyon on 27 and 28 March 1932.

[21] An invitation was addressed to PSIm for the reconstruction of the socialist unity among the LSI, while the proletarian one with communists was complained, but refusing the Bolshevik notion of power which would have dictatorship and terrorism as main fatal consequences.

On 4 and 5 June 1933, during the 4th convention of PSIm, the Direction identified as the main causes of the victory of fascism and nazism not only the misunderstanding of the two phenomena by Second and Third International, but also the paralysis provoked by disagreements and fratricidal fights within the action of masses which destroyed the faith in the future revolution.

An intermediate movement was formed among the Direction and it considered the creation of a sincere and effective agreement of proletarian organizations as the main task of the party, in order to give back to masses the faith in the future revolution and the necessary force to oppose the imperialism and transform the capitalist society into a socialist one.

[22] Despite the LSI was considered by the maximalist PSI as "the International of war and collaborationist reformism, den of social chauvinists", this kind of collaborative "elasticity" or spirit of understanding towards the London Bureau was a surprise.

While Leon Trotsky accused the merger of Spanish right and communist left into the POUM as a "surrender to centrism",[23] Italian maximalists considered it as a clear example of "reconstitution of the proletarian unity".

On 19 June 1933, while Adolf Hitler was conquering the power in Weimar Republic, a World Conference was held in Brussels with all the proletarian organizations not affiliated with Comintern nor Labour Socialist International.

[26] Mariani accused the division among the labour and socialist movement provoked by right and left sections, between social democratic and communist leaders, for the victories achieved by the fascist reaction in Italy and elsewhere.

The PSI-LSI Direction convened in Paris on 14 and 15 July 1935 and approved the motion in favour of the «realization of one of the main goals of workers: one Party, one syndical organization, one International», in order to support the quest of peace and, in case of an attack against the Soviet Union, to «defend Russia without any kind of compromises with any imperialism».

Among PSI-LSI, resistances against the Unity of Action Pact with PCd'I arose: Pietro Tresso and Nicola Di Bartolomeo, exponents of New Italian Opposition (Nuova Opposizione Italiana, NOI), stated that «the Popular Front would lead to the capitulation in Stalin's hands», considering «the constitution of a Fourth International as necessary».

[31] The debate within PSIm about the need of a new proletarian International saw the group of Balabanoff in favour of the Trotskyist proposal, and due to that the party accepted two meetings with dissident NOI exponents of PSI-LSI organized in September 1935.

Another meeting was held five days later, with the participation of Trotskyist Mario Bavassano, and the formation of an Agreement Committee (Comitato d’Intesa) was approved, pushing on Pietro Tresso, Alfonso Leonetti, Paolo Ravazzoli and other NOI leader in order to make them join to PSIm.

[34][35] Since the first days after the victory of the Popular Front, peasants began to occupy the lands of their owners,[36] and left activists started to request the amnesty for prisoners among the cities.

About thirty maximalist socialists came in Spain to join the Workers' Party of Marxist Unification (Partido Obrero de Unificación Marxista, POUM), the Spanish homologue and political referent of PSIm.

Among them there was Giuseppe Bogoni, who settled in Perpignano as a link officer with Aldo Garosci, the organizer of the Italian column armed and trained in Barcelona by Mario Angeloni.

(which remained to maximalists) beyond 1940, but it was dismantled after the end of WWII, joining the Italian Socialist Party of Proletarian Unity (Partito Socialista Italiano di Unità Proletaria, PSIUP).