Mrs Thomas brought an employment tribunal claim in connection with her grievances against her employer, Devon the Council. It was unclear exactly what her complaint was. After a grievance meeting she resigned and withdrew her tribunal claim. The tribunal formally dismissed the claim on withdrawal. Soon afterwards she submitted a second claim, this time alleging constructive unfair dismissal. A chairman decided that the two claims were "of the same tenor", and so res judicata. He therefore struck out the claim. Mrs Thomas appealed to the EAT.