53In any event, since it is the Commission alone which has the power to reduce ESF assistance, the decisions of the DAFSE of 30 July 1990 and of 1 September 1993 reducing the national financial contribution and demanding the repayment of certain sums (see paragraphs 11 and 12, above) are purely national decisions and are in no way attributable to a Community institution. They fall outside the purview of the Community judicature since it is for the competent national court to review the validity of national measures implementing Community acts relating to the aid at issue. In this case, the national court may, pursuant to Article 1 77 of the Treaty, refer to the Court of Justice a question as to the validity of those Community acts.