In France, education policies concerning children's home languages have recently changed, with the country's highly centralized and monolingual national education system now promoting inclusive language policies, specifically at the pre-primary level (M.E.N. (Ministère de l'Education Nationale). 2016. "Statégie langues vivantes." 22 janvier 2016. Paris). However, such prescribed practices run contrary to historically rooted monolingual ideologies and interpretations of the values of the "République" (Hélot, Christine. 2008. « Mais d'où est-ce qu'il sort ce bilinguisme? » La notion de bilinguisme dans l'espace scolaire français. In Gabriele Budach, Jürgen Erfurt & Melanie Kunkel (eds.), "Écoles Plurilingues -- Multilingual schools: Konzepte, Institutionen und Akteure. Internationale Perspecktiven," 55-80. Frankfurt: Peter Lang). Understanding the policies and ideologies influencing teachers' agency to implement inclusive language policies via their own classroom practices is vital to developing effective teacher education programs. In this paper, we analyze data from our research into pre-primary and primary school teachers' attitudes, beliefs, and knowledge about their pupils' plurilingualism and its place in the classroom, with the aim of answering the following research questions: what are some of the reported practiced language policies in these classrooms, and on which underlying ideological foundations have they been constructed? In order to uncover the ideological challenges to implementing plurilingual education approaches and language-supportive pedagogies, semi-directed interviews with eight pre-primary and primary school teachers working in low-resource contexts (primarily low-income families) were conducted, transcribed and analyzed using the constant comparative method.