On 7 June 1955, Joseph Bech, Luxembourg Foreign Minister, forwards to his British counterpart, Harold Macmillan, a letter in which he asks him to consider the possibility that a British representative might participate in the future work of the Intergovernmental Committee established by the Messina Conference.

On 15 June 1955, Harold Macmillan, British Foreign Secretary, forwards to his Luxembourg counterpart, Joseph Bech, a letter in which he thanks him for having invited a representative of the British Government to participate in the work of the Intergovernmental Committee established by the Messina Conference.

In July 1955, Johan Willem Beyen, Netherlands Foreign Minister, sends to his British counterpart, Harold Macmillan, a letter in which he invites the British Government to attend the first meeting of the Intergovernmental Committee established by the Messina Conference, due to be held on 9 July 1955 in Brussels.

In July 1995, Harold Macmillan, British Foreign Minister, sends a letter to his Netherlands counterpart, Johan Willem Beyen, in which he informs him that a representative of the United Kingdom will attend the first meeting of the Intergovernmental Committee established by the Messina Conference, due to be held on 9 July 1955 in Brussels.

On 18 November 1955, the British Government informs the Government of the Federal Republic of Germany (FRG) that it will not be able to participate in the Common Market because of its economic and political links with the Commonwealth countries.

On 9 December 1955, Pierre Pescatore, Legal Adviser to the Luxembourg Foreign Ministry, receives a note from the British Embassy in Luxembourg outlining the reservations of the British Government about the proposal for the Common Market.

In January 1956, the Department of Economic Cooperation at the Quai d’Orsay outlines the nature and the progress of the work of the Intergovernmental Committee established by the Messina Conference and sheds light, in particular, on British reservations about a new drive towards European integration.

On 4 February 1956, Maurice Couve de Murville, French Ambassador to the United States, forwards to Christian Pineau, French Foreign Minister, a telegram in which he summarises the conversations between the British Prime Minister, Anthony Eden, and the American President, Dwight D. Eisenhower, on European integration policy.

Le 11 février 1956, le journal financier anglais The Economist analyse les avantages et les inconvénients des différents plans émanant des Six et de l'Organisation européenne de coopération économique (OECE) pour gérer en commun l'utilisation pacifique de l'atome.

On 18 June 1956, André Clasen, Luxembourg Ambassador to London, sends Joseph Bech, Luxembourg Prime Minister and Foreign Minister, a note in which he outlines the content of the conversations between Edgar Faure, former French Prime Minister, and Anthony Nutting, Under-Secretary of State in the British Foreign Office, on the question of the United Kingdom’s participation in the revival of the European integration process.

In the House of Commons, on 5 July 1956, referring to the efforts being made to bring about a European revival, British MPs debate future relations between the United Kingdom and the Europe of the Six.

In October 1956, more than 50 eminent public figures from the United Kingdom publish a statement in which they advocate the United Kingdom’s participation in the negotiations on the European Common Market.

Am 5. Oktober 1956 berichtet die deutsche Wochenzeitung Rheinischer Merkur über die Debatten im Vereinigten Königreich über eine mögliche Teilnahme des Landes an der europäischen „Relance" und untersucht die spezielle Situation der britischen Wirtschaft angesichts der neuen europäischen Herausforderungen.

On 13 October 1956, the London weekly political magazine The New Statesman and Nation expresses its doubts about the advantages for the United Kingdom of an association with the Common Market envisaged by the six Member States of the European Coal and Steel Community (ECSC) or of the establishment of a free-trade area under the auspices of the Organisation for European Economic Cooperation (OEEC).

„Der letzte Bus.“ Am 19. Oktober 1956 illustriert der britische Karikaturist David Low im Zusammenhang mit der europäischen „Relance“ die Herausforderungen einer Beteiligung des Vereinigten Königreichs an den europäischen Integrationsbemühungen, aufgrund der privilegierten Handelsbeziehungen des Landes mit seinen Partnern im Commonwealth.

On 29 November 1956, the British Chancellor of the Exchequer, Harold Macmillan, forwards to Ludwig Erhard, German Minister for Economic Affairs, a telegram in which he emphasises the key points to be discussed at the negotiations on the proposal for a free-trade area under the auspices of the Organisation for European Economic Cooperation (OEEC).

On 17 January 1957, commenting on the visit to London by Paul-Henri Spaak, Belgian Foreign Minister and President of the Intergovernmental Conference on the Common Market and Euratom, the daily newspaper La Libre Belgique paints a picture of a United Kingdom torn between its preferential imperial links with the Commonwealth and possible accession to the European Economic Community (EEC).

Auf einem Kolloquium vom 25. bis 28. März 1987 in Rom anlässlich des dreißigsten Jahrestages der Unterzeichnung der Verträge zur Gründung der Europäischen Wirtschaftsgemeinschaft (EWG) und der Europäischen Atomgemeinschaft (EAG oder Euratom) erläutert Baron Jean-Charles Snoy et d'Oppuers, ehemaliger Generalsekretär des belgischen Außenministeriums und ehemaliger belgischer Delegationsleiter im Regierungsausschuss von Messina und später in der Regierungskonferenz für den Gemeinsamen Markt und Euratom, die handelspolitischen Gründe, die das Vereinigte Königreich von einer Teilnahme an der Europäischen Wirtschaftsgemeinschaft (EWG) abhielten.

In an interview conducted on 26 March 1997 in Brussels during the commemorative events held to mark the 40th anniversary of the signing of the Treaties establishing the European Economic Community (EEC) and the European Atomic Energy Community (EAEC or Euratom), Jean-François Deniau, former member of the French delegation to the Organisation for European Economic Cooperation (OEEC) and the Intergovernmental Conference on the Common Market and Euratom, explains the United Kingdom’s position on the revival of the European integration process.