At that moment Johan Willem Beyen (Netherlands Minister for Foreign Affairs) took the initiative to revive an idea, based on the Ouchy Convention of 1932, he had already put forward in December 1952 and February 1953 for the European Political Community (EPC).
He proposed that the member states of the European Coal and Steel Community would develop a common market without customs duties or import quotas instead of a sector-based integration which had been the option taken by the ECSC.
[1] Beyen sent a memorandum to his Benelux colleagues Paul-Henri Spaak (Belgium) and Joseph Bech (Luxembourg) on 4 April 1955 in which he proposed his idea of a customs union.
In the memorandum the Benelux proposed the establishment of an Economic Community based on a general common market and a sectoral approach for transport and energy, especially nuclear energy (the last was in the line of the approach taken with the ECSC).
The common market was to be achieved by a gradual reduction of trade restriction and custom tariffs.