Throughout its early years, the Common Assembly was suspended in two states. First and foremost, it existed as the parliamentary assembly of the ECSC, whose members sought to build an institution on the basis of a legal and political reality as well as political aspirations of their own. At the same time, those same members, complemented with colleagues from the Council of Europe's Consultative Assembly, formed the Ad Hoc Assembly. This institution was making plans that far extended the reality of the Common Assembly. Between 1952 and 1954, these institutions existed alongside each other. Any analysis of the early years of the Common Assembly has to reckon with this fact, and acknowledge that the proceedings of the Ad Hoc Assembly reflected experiences in the Common Assembly and thus contained aspirations for its reform.

During these two years, the members were torn between discontentment and hope. Discontentment with the very limited role they had been given by the negotiators on the Treaty of Paris. They were only there to control the High Authority and, as an ultimate sanction, to enact a motion of censure against it. Hope they derived from the idea that their institution would actually be turned into a democratically elected people's chamber through a constitutional blueprint. This hope eventually withered as the EPC hung in the balance, but this did not deter the members of the Ad Hoc Assembly to further pursue their ideals in the context of the ECSC. Their plans for an EPC had been firmly rooted in the constitutional repertoire. These ideas remained largely unchanged, but as the momentum for grand designs of European integration waned, the members of the Common Assembly sought alternative ways to pursue their political aspirations. They came up with ways of strengthening their role and competences by cultivating new practices, rather than going back to the drawing board. As a result, the practices underpinning the constitutional repertoire became much more incremental and practice-oriented than had been the case during the years of the European Movement and the Ad Hoc Assembly.