R (Midcounties Co-Operative Limited) v Wyre ForestDistrict Council & Tesco Stores Limited & Others  EWCA Civ 841
In this case, the Court of Appeal held that such a provision would be unlawful. The Court considered the lawfulness of a planning permission for the construction of a supermarket that specified maximum floor space allocations but provided for the limits to be changed if the local planning authority agreed in writing. The objector, an operator of an existing supermarket, argued that the provision permitted uncertain variations, enabled development to occur which had not been applied for, assessed and permitted, and sidestepped the statutory process for the grant and variation of planning permissions. The Court upheld the planning permission but held that the provision allowing for the variation should be deleted.