On 4 December 1951, Jacques Duclos, leader of the Communist group in the French National Assembly, sends a letter to the Central Works Council of the steel company Union sidérurgique du Nord de la France (Usinor), in which he sets out the reasons why the French Communist Party has decided to vote against the ratification of the Treaty establishing the European Coal and Steel Community (ECSC) and particularly emphasises the dangers of the Schuman Plan for France.