Fundamental British Values are regarded as a tool in the UK counter-terror strategy to support the Prevent Duty (2015) of steering pupils away from extremism. 'Fundamental British Values' is understood here as a label, developed in the wake of the 'end of multiculturalism' rhetoric, and is promoted as a new form of discourse for schools. I explore the implications and risks of this vocabulary both for the classroom and for society at large by examining each of the terms 'fundamental', 'British', and 'values' through a form of analysis, influenced by Fairclough. Potential practical outcomes, including the formation of an 'us and them' narrative, together with a reductive notion of Britishness, and a risked sense of alienation, are identified. In the promotion of values, language can have 'hidden effects' which may be perpetuated through unconsidered refrain in classrooms and in staffrooms. The Ofsted requirement upon schools to promote these values, suggests a need for a critical and sensitive understanding in order to be aware of, and to minimise, the potential risks affecting social cohesion.