In a context marked by the paradox of abundant liquidity but insufficient long-term investment, Eric Lombard, Chief Executive Officer of Caisse des Dépôts, asked Bernard Attali, Honorary Senior Advisor to the Cour des Comptes, to bring together a team of economists and financial practitioners from various backgrounds to formulate some ideas and actions. Under his chairmanship, Laurent Zylberberg, Director of Institutional, International and European Relations at CDC, was entrusted with the task of leading this group. The Institution is today publishing these guidelines to promote the transition to a sustainable economy in the report "Long term investment, an immediate need". These national and European reflections will be implemented within the framework of European Long Term Investors Association (ELTI). The French Presidency of the European Union offers us a unique opportunity to organise this debate.