The right of citizens to high-quality e-Government services makes one-stop service offerings an essential feature for e-Government. Offering onestop services presents many operational implications; an one-stop service provision (OSP) architecture is needed that, by means of a layered approach, provides facilities to refer to, invoke and combine e-Government services in a uniform way, in the context of cross-organisational workflows. Although enabling technologies for all the layers of such an architecture are quickly evolving (XML, WSDL, UDDI, WFMS et al) two major issues that need to be solved are (a) abstracting the heterogeneity of the e-Government services that need to be integrated and (b) identifying an appropriate style for cross-organisational workflow control, somewhere in between the fully centralised and peer-to-peer extremes. This paper presents an abstract layered OSP architecture, identifies some major enabling technologies and briefly discusses those two issues.