Court: Court of Appeal (England and Wales) Citation: [1975] 1 WLR 1346 Facts: In Tanner v Tanner, Mr. Tanner and Ms. Tanner were in a relationship and had two children together, although they were not married. Mr. Tanner purchased a house and asked Ms. Tanner to move in with their children, stating that this arrangement would provide a stable home for the family. Relying on this assurance, Ms. Tanner moved in with the children and gave up her previous tenancy. Later, Mr. Tanner sought to evict Ms. Tanner from the house, leading to a legal dispute over her right to remain in the property. Legal Issues: Constructive Trust and Proprietary Estoppel: Whether Mr. Tanner’s promise and Ms. Tanner’s reliance on that promise created a constructive trust or established grounds for proprietary estoppel. Rights of Occupation and Equity: Whether Ms. Tanner was entitled to equitable rights of occupation given her reliance on Mr. Tanner’s promise and her sacrifice of secure housing to move into his property. Decision: The Court of Appeal ruled in favor of Ms. Tanner, finding that she had a right to remain in the house for the children’s upbringing due to the reliance she placed on Mr. Tanner's promise. The court recognized that Mr. Tanner’s assurance, combined with Ms. Tanner’s action of surrendering her tenancy, created an equitable right. The judgment relied on the principle of proprietary estoppel and a constructive trust, acknowledging that Ms. Tanner’s detrimental reliance entitled her to an equitable interest in the property, specifically a right of occupation. Lord Denning MR reasoned that it would be inequitable to permit Mr. Tanner to revoke his promise and displace Ms. Tanner and the children after she had acted to her detriment. Significance: Tanner v Tanner is a significant case in family and property law, establishing that non-marital partners may have an equitable right to occupy a property based on assurances and their reliance on those promises, especially when they incur detriment. The case illustrates how English courts use proprietary estoppel and constructive trust principles to protect individuals who rely on promises of accommodation, particularly in family or quasi-family contexts. This case is frequently referenced in discussions on cohabitation rights and equitable interests in family property disputes.