MADLANGA J account of the difficulties raised by the ‘closed-shop system’ in certain countries, the Conference in this connection considered that it was undesirable to introduce into the Convention a rule under which ‘no one may be compelled to belong to an association’ which features in [Article 20 para 2 of] the United Nations Universal Declaration”.43 The Court held: “The Court does not consider it necessary to answer this question on this occasion. The Court recalls, however, that the right to form and to join trade unions is a special aspect of freedom of association . . . it adds that the notion of a freedom implies some measure of freedom of choice as to its exercise. Assuming for the sake of argument that, for the reasons given in the above-cited passage from the travaux préparatoires, a general rule such as that in Article 20 para 2 of the Universal Declaration of Human Rights was deliberately omitted from, and so cannot be regarded as itself enshrined in, the Convention, it does not follow that the negative aspect of a person’s freedom of association falls completely outside the ambit of Article 11 . . . and that each and every compulsion to join a particular trade union is compatible with the intention of that provision. To construe Article 11 as permitting every kind of compulsion in the field of trade union membership would strike at the very substance of the freedom it is designed to guarantee . . .”44 It is significant that – despite proceeding from an apparent assumption that Article 11 did not encompass a right of the nature of that protected in paragraph 2 of was advised by technical committees, and the reports of these committees on the drafts are the equivalent of the travaux préparatoires, relied upon by the international tribunals. Such background material can provide a context for the interpretation of the Constitution and, where it serves that purpose, I can see no reason why such evidence should be excluded.” 43 This extract from the travaux préparatoires is quoted in Young above n 37 at para 51. Article 20 of the Universal Declaration of Human Rights (UDHR), which is referred to in the extract, provides: 44 “(1) Everyone has the right to freedom of peaceful assembly and association. (2) No one may be compelled to belong to an association.” Young above n 37 at para 52. 16