It has been assumed for the purposes of this Q&A that the withholding of consent relates to an alienation request (ie a request was to assign/underlet/charge/part with possession). If, however, it related to alterations, the response will need to be revisited as it is governed by different case law and statutory provisions. As a starting point in that regard, see: Alterations and improvements for property disputes lawyers—overview. Unreasonable withholding of consent As set out in Practice Note: Landlord's consent to assign or underlet, in the case of Ansa Logistics v Towerbeg, the High Court confirmed that consent to assign/underlet cannot normally be refused simply because the landlord is able to identify a breach of covenant. The question is whether the breach of covenant is of such a nature as to justify the refusal of consent. See commentary: