The number of secondary school students in England being placed in "internal exclusion" — a disciplinary measure where students are removed from their regular classes but remain on school premises — has risen sharply over the past three years. According to data analyzed by Arbor, a management system used by 13,000 schools, the proportion of secondary students excluded internally increased from 5% in the 2022/23 academic year to 13% in 2025/26, a 160% increase. Disadvantaged students are disproportionately affected, with 22% of them being removed from lessons at least once in the 2025/26 year, compared to 8% in 2022/23 — a 175% rise. For non-disadvantaged students, the rate was 10%. Students with special educational needs and disabilities (Send), who often have education, health and care plans, also face higher rates, with 18% of them being internally excluded at least once in the most recent academic year. Internal exclusion is a disciplinary action that differs from permanent exclusion or short-term suspensions, which require students to leave school. Instead, internally excluded students are kept on campus, often in a separate area sometimes referred to as an "isolation room," and are returned to their classes after the exclusion period. This approach aims to manage behavior while keeping students within the school environment. The data shows that internal exclusions are rare among primary students, with fewer than 1% of under-11s affected in 2025/26. However, the actual number may be higher, as Arbor does not collect data from all schools. Opinions on the impact of internal exclusion are divided. Critics argue that it can harm students' mental health and disrupt their learning, while others see it as a necessary tool for managing classroom behavior. James Weatherill, CEO and co-founder of Arbor, highlighted that the significant increase, especially among disadvantaged students, raises concerns about the underlying reasons. He called for a more comprehensive understanding of how many students are being excluded, how long they are removed, and the effects of this practice. Various education experts and leaders have weighed in on the issue. Pepe Di'Iasio, general secretary of the Association of School and College Leaders, noted that internal exclusions are typically used only after other methods of behavior management have failed and are a less severe alternative to external exclusion. Lily Wielar, a researcher at the Education Policy Institute, emphasized that classroom removal has become a common part of behavior management in secondary schools, suggesting a need for more research and legal protections for excluded students. Tom Bennett, a leading behavior management expert, viewed internal exclusion as a way to hold students accountable without exposing them to unsupportive environments. Dame Rachel de Souza, England’s children’s commissioner, stressed the importance of ensuring that excluded students continue to receive quality education and are supported to learn with their peers when possible. The Department for Education has been asked for a response.