The LEADER proposal deals with the development to a conceptual level of a Lead Fast Reactor Industrial size plant and of a scaled demonstrator of the LFR technology. The proposal is based on previous achievements obtained during the 6th FP of the EU in the ELSY project but takes into account the indications emerged from the European Strategic Research Agenda as well as the main goals of the European Industrial Initiative on Fission. As a consequence the project is strongly committed to the conceptual design of a scaled/pilot plant to be constructed in the relatively short term. The focus of the first part of activity will be the resolutions of the key issues emerged in the frame of the ELSY project to reach a new reference reactor configuration. This updated reactor configuration of an industrial size LFR will be used to design a low cost and fully representative scaled down prototype of a suitable size. The project foresee an important involvement of End-Users and Safety Authorities from the beginning of the design process to help the plant conception and to assure high safety standards. Education and Training activities are included in a specific work package where European Universities are directly involved with the aim to grow-up the future nuclear energy designer. The LEADER projects takes strongly into account the others already proposed or on-going EU projects. All projects dedicated to R&D and material developments, projects dedicated to the development of ADS systems for transmutation or related to the development of fast reactors (VELLA, CDT, CP-ESFR, GETMAT, FAIRFUELS, ACSEPT, EUFRAT, F-BRIDGE, ACSEPT, ACTINET-I3, THINS) have strong synergies with LEADER toward the development of a Lead cooled fast reactor system. The project Partners are convinced that fostering the European efforts towards a LFR demonstration/pilot plant realization would be very beneficial, will speed up the development needed and establish Europe as a leader in this field.