On 16 May 1961, Pierre Pescatore, Political Director in the Luxembourg Foreign Ministry, drafts a summary note on the progress in the ongoing negotiations on the plan to merge the Community executive bodies, in a bid to clarify Luxembourg’s position on this matter.

In this note dated 3 October 1963, the Permanent Representatives Committee sets out the problems raised, given the current state of the texts in force, by the potential merger of the two Commissions and the High Authority, and of the three Councils.

On 27 January 1964, Pierre Werner, Minister without portfolio and leader of the Luxembourg Government, issues a statement on the problem of merging the European executives and on its implications for Luxembourg.

Le 31 juillet 1964, Günther Harkort, ambassadeur de la République fédérale d'Allemagne (RFA) à Bruxelles, informe sur la réunion commune des Conseils des ministres de la CEE et de Euratom et dresse le bilan des négociations sur la fusion des exécutifs des Communautés européennes.

On 22 February 1965, the Belgian daily newspaper Le Soir outlines the implications for the city of Luxembourg, as the seat of several Community institutions, of the future Treaty merging the executive bodies of the European Communities.

In this interview, Edmund Wellenstein, Secretary-General of the High Authority of the European Coal and Steel Community (ECSC) between 1960 and 1967, explains the conditions in which the Community executive bodies were merged between 1965 and 1967, particularly identifying the need to defend the historical prerogatives of the High Authority.

At the end of a Council of Ministers of the Six, the Luxembourg Minister for Foreign Affairs, Eugène Schaus, explains the position of the Grand Duchy on merging the executives.