The last four decades have been characterised by a movement towards inclusive education globally. While Ireland has been slow to move in that direction significant progress has been made in providing support for students with special educational needs (SEN) in Irish schools. This study examines how the most recent Department of Education (DE) policy initiative to provide additional teaching support to students with SEN under a ‘new model’ introduced in Circular 0013/2017 (DES, 2017a) is understood and mediated by teachers and principals in mainstream primary schools in a Dublin postal district. An explanatory sequential design situated within a pragmatic paradigm was employed. In phase one principals, mainstream class teachers and SEN teachers (N=73) completed a survey, and in phase two one-to-one and focus group interviews were conducted in a Delivering Equality of Opportunity in Schools (DEIS) Band One Junior primary school in the same postal district. Analysis of the data sets were conducted using descriptive statistics and thematic analysis and the findings of the study are presented under four themes. The data captured the attitudes, beliefs and perceptions of principals and teachers towards the ‘new model’ and its impact on their practice. The findings show that teachers and principals consider themselves advocates for inclusion but believe that all students cannot be included effectively in the mainstream class. They question the lack of clarity and transparency around the ‘complex’ needs’ component of the model. While some teachers and principals welcomed the increased agency provided under the ‘new model’, others suggested that this transferred the responsibility from the National Council for Special Education (NCSE) and the DE to schools without providing the necessary level of support which is a challenge. The findings of this study raise important considerations and have implications for policy, practice and future research if ‘truly inclusive schools’ are to be realised.