Fallacious arguments and manipulative rhetorical strategies are widely known to riddle political deliberation and erode its moral potential. In this paper, I argue we need to take seriously the deliberative costs of two rarely-noted – but increasingly common – types of dialectical manoeuvres. These ‘meta-argument allegations’ centre on protestations that an interlocutor’s speech is wrongfully offensive, or will trigger unwanted social consequences. These manoeuvres are meta-argument in the sense that they do not interrogate the soundness of an opponent’s argumentation, but provide external commentaries upon the argument. They are allegations because they imply moral wrongdoing. I argue meta-argument allegations exert a damaging influence on political deliberation by violating norms of reasoned deliberation, and derailing deliberations about the matter at hand. Worse, they license further actions aiming to silence, punish and deter – even as they incite the original speaker to respond in kind, levelling retaliatory allegations of offence and harm. Ultimately, I aim to establish the principle of ‘deliberative tolerance’ – understood as a principled resistance to employing meta-argument allegations – as a key norm and virtue of ideal argumentation.