Neosocialism was a political faction that existed in France and Belgium during the 1930s and which included several revisionist tendencies in the French Section of the Workers' International(SFIO).
During the 1930s, the faction gradually distanced itself from revolutionary Marxism and reformist socialism while stopping short of merging into traditional class-collaborative socialism of radical-socialist progressivism. Instead, they advocated a revolution from above which they termed as a constructive revolution. In France, this brought them into conflict with the Socialist Party's traditional policy of anti-governmentalism and the neosocialists were expelled from SFIO.
From the start, this linked them to fascist politics in France and neosocialists expressed admiration for Italian Fascism. This tendency later emerged as an ideological orientation in its own right with the Neosocialist Party which advocated authoritarianism and antisemitic policies as well as intimate cooperation with the Nazis.
https://en.wikipedia.org/wiki/Neosocialism
At request of @Origami Reef