The biggest research project on green purchasing known in Europe started in 2001. RELIEF, by full name "Environmental Relief Potential Of Urban Action On Avoidance And Detoxification Of Waste Streams Through Green Public Procurement", is carried out by a consortium of research partners. RELIEF will develop an extensive set of data on the environmental benefits which are potentially achievable through green purchasing. Methods will be developed on environmental assessment of products, assessment of public buying power and evaluation of market conditions. Based on local case studies and priority identification, scenarios will be developed for the application of green purchasing at a European level and their environmental effects will be calculated. The results will be combined with research on innovation fostering contractual arrangements and a legal analysis. The final outcomes (policy recommendations, procurement guidelines, trade code) will be discussed in roundtables and lead to a European Cities for Green Purchasing Campaign.