Before and during World War II, the Breton nationalist movements were generally associated with anti-French and the political right-wing. The extent to which this led to collaboration with the Nazi occupiers of France during the war, together with their motivations, is a matter of historical controversy.
Before the occupation, Breton nationalists were split between regionalism, federalism, and separatism. Essentially these factions, though divided, remained insensitive and frankly hostile to democratic ideals. Among these groups, only the openly separatist Breton National Party remained organized; dissolved in 1939, it was rapidly reconstituted in the autumn of 1940 and became the most active political party in Brittany under the Occupation. Having broken in 1931 from regionalism, its founders (Olier Mordrel and François Debeauvais) were inspired by the Irish Revolution and played the nationalist card. When war broke out, the Breton National Party chose a position of strict neutrality. This party's ideas were anti-democratic and complacent towards xenophobia and antisemitism, influenced by German racism and close to all the varieties of European fascism. During the war the activism of the Breton National Party completely dominated the other branches of the Breton movement, who found themselves discredited.
On 15 December 1940 a "petition" signed by 46 Bretons requesting "administrative autonomy" in the confines of a united France was sent to Philippe Pétain. On 22 January 1941, the Vichy government named Hervé Budes de Guébriant President of the National Commission for Agricultural Cooperation. The daily journal La Bretagne was created by Yann Fouéré on 21 March 1941. It took a regionalist point of view, opposed to the separatism of the Breton National Party. An appreciable number of Breton nationalists were also to be found in the Consultative Committee of Brittany, created on 11 October 1942 by Jean Quénette, prefect of the region of Brittany. "An organization of study and work", according to Yvonnig Gicquel, it did not wield any executive or decisive powers (against the wishes of the provincial parliament which conceived the adoption of the Breton regionalist doctrine). The will of its members (including members of the Breton National Party Yann Fouéré, Joseph Martray, etc.) was to transform this consultative committee into a true legislative assembly to tackle regional problems. Many of its members were to resurface when CELIB was created.