Why the final planned Tribal-class ships disappeared

What killed off the last planned Tribal-class destroyers?

The outbreak of the Second World War and the resulting change in naval priorities ended the remaining programme.

The Second World War ended the final part of the planned Tribal-class programme. Wartime needs changed which ships and programmes received priority. The Royal Navy had thought in terms of completing whole flotillas, but that peacetime logic no longer controlled procurement. The missing ships reflect mobilization and changed requirements rather than a simple rejection of the class.