17.

Under the Netherlands legislation, the fact that the claimant has worked in more than one Member State places him at a disadvantage compared with a worker who, although he may have been engaged in a variety of occupations, has always worked in the Netherlands. As the defendant itself admitted, if Mr Moscato had worked only in the Netherlands, even moving from one area to another, the operation of the risk-selection rule would not have entailed for him the adverse effects at issue. The root cause of the discrimination is therefore the fact of his having worked in different Member States. In practice, a person who moves to the Netherlands in order to work there must start afresh so far as his insurance record is concerned. The Netherlands legislation is not in fact concerned with the migrant worker's occupational and insurance record, which is not taken into account by the risk-selection provisions. Consequently, those rules, as framed and applied, interfere with freedom of movement for workers. Those who wish to work in the Netherlands — especially those who are older and presumably more vulnerable to illness — run the risk of losing the right to invalidity benefits, however long their working history may be. Thus workers from other Member States are discouraged from moving to work in the Netherlands. As far as the present case is concerned, the national legislation must not contravene the general principle of freedom of movement or the specific rules laid down by the Treaty with regard to the calculation of insurance periods for migrant workers. Thus, as we see, the way in which the risk-selection provisions may be applied to the claimant is limited directly by the Treaty. The migrant worker's right to aggregation of insurance periods is guaranteed by Article 51 as a natural corollary to freedom of movement: it is a Community right — based on the Treaty, even before it was laid down by the Regulation — the enjoyment of which may not be impaired by risk-selection provisions entailing the effects ascribed under Netherlands law. Consequently, there is only one correct way to read those provisions and that is in accordance with the Treaty and with the Regulation, deriving from one or other of those sources of Community law the criteria for their application to migrant workers. If the provisions in question are read in that manner, this will, as far as possible, prevent the Netherlands risk-selection provisions from being construed in such a way ‘as to discourage’ — to quote the Court in Van Munster ( 3 ) — ‘a migrant worker from actually exercising his right to freedom of movement’. In the present case, that interpretative criterion must be observed, with this note of caution: as has been pointed out, the principles and rules of Community law referred to by the national court bear upon the provisions and operation of the national legislation on risk-selection: they aim not only to prevent freedom of movement for workers from being undermined, but also to prevent in practice national rules of that kind from going beyond the limits of their proper application and thereby denying migrant workers the right to welfare benefits to which they are entitled.