In Belgium, two main trends are opposed :
- in one hand the politicians and the big monopolies wish to ratify this treaty which will allow to freely exchange goods and services amongst the countries of the community,
- and in the other hand the socialists and the communists who are afraid of an increase of competition, of a disappearance of small firms and of the creation of cartels (tacit collusion) by the large monopolistic groups.
According to their trends, the newspapers of that time reflect these various opinions.

Some others such as « La Libre Belgique » display their scepticism with regard to the alignment of currencies : : « We can see that as far as the currencies convertibility isn’t guaranteed , all the customs duties will probably be ineffective. »

« Vers l’Avenir » reveals that Belgium already thinks to set up the European institutions headquarter in Brussels : « The government is ready for the creation of an European district on the Belgian territory. »

The newspaper “Le Soir” is particularly interested in the energy resources essential for the development of the Common Market. Two solutions are considered :
- the association of the overseas territories with the Common Market (in order to exchange energy giving raw material for a Common Investment Policy in these regions often underdeveloped as well as the progressive suppression of customs duties),
- and the Euratom treaty to quickly acquire industrial and technical means necessary for nuclear energy production.

According to the newspaper « La Wallonie », the signing of the Common Market and the Euratom treaties have produced a wave of satisfaction in the European press, even in England:
« England realizes that it would be interesting to make part of the Common Market. That will allow England to increase its national production. England could also easily sell its products in a wide free trade zone. »