In so far as progressive abolition of customs duties and quantitative restrictions between Member States may result in prices likely to jeopardize the attainment of the objectives set out in Article 39, each Memer State shall, during the transitional period, be entitled to apply to particular products, in a non-discriminatory manner and in substitution for quotas and to such an extent as shall not impede the expansion of the volume of trade provided for in Article 45 (2), a system of minimum prices below which imports may be either: ? temporarily suspended or reduced; or ? allowed, but subjected to the condition that they are made at aprice higher than the minimum price for the product concerned.