Many governments worldwide are establishing one-stop portals to provide access to various public services based on the needs of citizens or businesses and not the internal structure of the government. A critical support for such one-stop portals is a workflow infrastructure, supporting the matching of the needs against provided services and coordination of the implementing processes, often spanning several government agencies. This paper describes a generic workflow infrastructure for one-stop government - GovWF. GovWF supports the operations of a Virtual Government Organization - a hierarchy of agencies providing collectively a set of public services, while offering a uniform one-agency view to its customers. Conceptual and formal models are provided to rigorously describe the operations of GovWF. We describe how GovWF is implemented and also present a case study for illustration.