France has been a politically and ideologically divided country for centuries prior to the Second World War. The first great division can go back to the 16th century Wars of Religion between Catholics and Reformed Christians. Later on, several parties, as we can call them that even though they looked very much like factions, played a role in the Ancien Regime such as the parti dévot ( members of the secret society Company of the Blessed Sacrements ) or the Ultra Catholic, …Etc

The French Revolution also brought this division to the people. There is little doubt that even during the Ancien Régime the people was divided on some questions, the Revolution and the regimes that followed allowed them to voice and show it. While studying the political evolution of France during the 19th century there has never been a true moment of real union between the French. In terms of politic, it was only in 1879 that the Third Republic have a truly republican government ( before, including the President Mac-Mahon, most were of various monarchist tendencies ). However, even with a republican Republic the division was important in all level of society.

The Sacred Union during WW1 united most of France's political and religious ideologies, except some far-right movements, with the goal to win the war as a one united country. WW1 was finally the time for the victory of the idea of Republic. However what kind of republic was still a question that divided most of the people. Post-War, France was in a very difficult position despite being one of the victors. 50% of the farmers were dead or incapacitated, the debt, close to 31 billion francs was enormous and all sorts of other elements. As such, many thought that to help France get its pre-war situation was to continue the Sacred Union in the 1919 legislative elections. However, the left ( the SFIO, the radical socialists, …etc ) refused as they were in internal crisis partly due to the question of the Bolshevism. While the left was divided the centre and right on the other hand united and formed the bloc national, a coalition. Most of the right was there but not all. The Action Française, a far-right, mostly anti-Semitic, monarchist league lead by the famous Charles Maurras did not took part. In the 1924 elections, things changed. The left managed to win a significant part of the seats and formed, as a way to counter the bloc national, the Cartel des Gauches ( Lefts Cartel ). As such the division was still very powerful in France during the interwar period. The never-ending form conflict between left and right, very old in France, was very present at the time.

Plus, the Third Republic was constantly in the line of fire of the antiparlementaristes. I am not sure I have found a proper translation but I supposed one can understand what it means quite easily. The corruption, the cost, the absenteeism in the Parliament were constantly criticized, and not without reason at the time, by both the far-left and the far right parties as well as the leagues, which is something else I need to talk about. Antiparlementarisme is not something new to the interwar period as it existed before ( the boulangisme ) but it was extremely important in the debates.

The 1920s and 1930s was the apogee of the rise of the far-right leagues. Inspired by previous movements like the boulangisme. There is no general pattern to the leagues except that they were right wings and against parliamentary republicanism ( it does not mean all were against the republic system ). The two most famous were the Action Française which I described above and the Camelots du Roi, the arm of the AF. Monarchist, anti-semitic, anti-immigration, popular among the Parisian working class. A lot of violence resulted of their actions and anti-Bolshevik fight, assassinations, riots,…Etc When WW2 came, the difficulty to understand the motivations of the AF and Camelots' motivations came to light as the members took very different paths, which showed how complicated their opinion was. Daniel Cordier, still alive, was a Resistant and secretary to Jean Moulin, Pierre Messmer a future Prime Minister was a Resistant. On the other hand, Joseph Darnand hardily fought the Germans in 1940 before becoming one of the most prominent Vichy member. Jacques de Mahieu joined the SS Division Charlemagne. The most important league in number, the Croix-de-Feu was formed with veterans of WW1. From 1927 to 1936 the CdF was one of the most visible league in France. They were far-rightists however moderates, nationalists but republicans. The political program of their leader, de la Rocque, won them a lot of support even from those who could not join them ( women, not veterans, …Etc ). Among other things, de la Rocque proposed a minimum wages, women's vote, paid leave, insurances,…Etc Many ideas that would later be associated with the Front Populaire in the late 1930. In February 1934, the political disorder lead to a manifestation ( due to the Stavisky case ) and then a riot, causing 15 deaths and many injuries. The rioters were mostly from far-right groups and the CdF was part of it. The CdF was ultra-patriotic, anti-immigration in a time when France welcomed many emigres from countries such as Russia or Spain. However, the true extent of their nationalism is debated. It does not seem they were anti-Semitic ( at least not fundamentally ) nor did they prone violence as a line of conduct, which does not mean they were not violent. Were they truly fascist or not is debated but many far-right groups of fascist tendencies existed and had an important weight in France. In France however, the historiography tends not to oppose a fascists and anti-fascists as in other countries but more the traditional left and right.

There also exist far-left leagues and groups of course, which I am not very knowledgeable about. The anarchists were still very active, although not as much as in the 19th century. Maurice Plateau, an important Camelot was assassinated by the militant Germaine Breton.

The years 1934,1935 and 1936 are marked by very important demonstrations and riots. The left was still divided between the communists, the SFIO and the radicals. All were engaged in the anti-fascist race to win the coming elections but could not agree. Most suspected the Communist Party to obey Moscow, the radicals were suspected to be turning toward the right,…Etc The 1936 elections changed the side of things. The left won and the SFIO had the majority. The Front Populaire was formed to block the right. Most of the left was present in the Front Populaire ( SFIO, Radicals, Communists and all sorts of smaller parties ). The CdF no longer existed but de la Rocque had formed the Parti Social Français ( Social French Party ) which was massive with perhaps a million voters.

Léon Blum, member of the SFIO became President of the Council of Ministers, de facto the chief of the government ( during the Third Republic the President of the Republic was very weak, almost honorific ). European politics also played a huge role in the division of the French. A large part of the population, generally in the left but the right as well, was pacifist since the end of WW1 ( Never Again! ). The Spanish Civil War divided the population between pro-interventionists and pacifists as well as between republican sympathizers and nationalist sympathizers. The question of the rearmament, three years before the war, was a debate in the government. In 1938, Blum resigned and the Front Populaire was destroyed. Edouard Daladier came to power. I will let someone else with more knowledge of the immediate beginning of the war go into details of Daladier's mandate and the year 1939.

As you have seen, the French were extremely divided not only pre-war but almost always. Just in the 1930 during Albert Lebrun's presidency, there has been 19 different governments in 8 years ( 1932 to 1940 ) plus a month of a Pétain government before his coup d'état. The longest government lasted barely 10 months and the shortest was 3 days. Before Lebrun, the radical President Doumer had been murdered by a White Russian. Doumergue's presidency from 1924 to 1931 had 15 governments ! As such, for the entire interwar period France did not have a single stable government. One could go into the details of each of these governments, the role of the Communists,…Etc

Sources :

Histoire de France by Jean Carpentier and François Lebrun

La République souveraine, histoire de la vie politique en France de 1879 à 1939 by René Rémond

Les Croix-deFeu et l'antisémitisme by Richard Millman Online