Professional support processes are critical for the establishment and maintenance of community health worker programmes. This paper reports on three public hearings held in England, UK, that were conducted as part of a national study into approaches to develop and support lay people in public health roles. Individuals with relevant theoretical or practical expertise, including lay activists, presented evidence in public as expert witnesses. Formal presentations, questions and plenary discussions were recorded and later analysed as qualitative data. This paper presents the results and critically examines emergent issues relating to the sustainability of lay health worker programmes. Consideration is given to the diversity of contemporary practice in England. Barriers seen to affect sustainability included organizational culture and onerous bureaucratic processes. Major themes emerging from the expert evidence included recruitment and training strategies, financial support and the need for a robust infrastructure. The expert hearings, in creating a public space for deliberation, opened up discussion on the levels and type of programme support required to foster lay health worker programmes. The paper concludes that professional support needs to be accompanied by a reorientation of public services to support lay engagement in programme delivery.