This study advances both psychological contract (PC) and psychological capital (PsyCap) research by testing a novel theoretical model predicting likely worker response, as a joint function of an individual's level of PsyCap and PC type, to perceived failure by the organisation to meet its obligations to the worker–organisation relationship. With a large emergency services organisation using volunteer workers as the research context, the study presents the first empirical evidence from a sample of 592 volunteers that the integrated application of PC and PsyCap theory can contribute to a better understanding of individual responses to an organisation's failure to affirm ongoing support for the volunteer–organisation relationship.