THE SAME IS NOT THE CASE WITH ARTICLE 97 .
8 CONSEQUENTLY, IN ORDER TO ASCERTAIN WHETHER OR NOT THEY ARE FACED WITH INTERNAL TAXATION THE CONFORMITY OF WHICH WITH THE TREATY THEY ARE BOUND TO ASCERTAIN, THE SAID COURTS MUST BE IN A POSITION TO DECIDE WHETHER THE MEMBER STATE IN QUESTION HAS OR HAS NOT APPLIED ARTICLE 97 .
IT IS THEREFORE SOLELY IN THE LIGHT OF THIS REQUIREMENT THAT THE QUESTIONS SUBMITTED SHOULD BE CONSIDERED .
QUESTION 1(A )
9 IN QUESTION 1(A ) THE COURT MAKING THE REFERENCE ASKS THE COURT OF JUSTICE TO GIVE AN INTERPRETATION OF THE EXPRESSION USED IN THE FIRST PARAGRAPH OF ARTICLE 97 OF THE TREATY, ACCORDING TO WHICH THE MEMBER STATES MAY ESTABLISH AVERAGE RATES, PROVIDED THAT THERE IS NO INFRINGEMENT OF THE PRINCIPLES LAID DOWN IN ARTICLE 95 .
10 THE ABOVEMENTIONED POWER, MADE AVAILABLE TO MEMBER STATES WHICH LEVY A TURNOVER TAX CALCULATED ON A CUMULATIVE MULTI-STAGE TAX SYSTEM, MUST BE UNDERSTOOD IN THE LIGHT OF THE DIFFICULTIES ENCOUNTERED IN THE APPLICATION OF THE PROVISIONS OF ARTICLE 95 WITHIN THE FRAMEWORK OF SUCH A SYSTEM .
11 IN FACT IN SUCH A SYSTEM THE AGGREGATE AMOUNT OF SUCCESSIVE IMPOSITIONS OF TURNOVER TAX DIRECTLY OR INDIRECTLY BORNE BY DOMESTIC PRODUCTS, WHICH CONSTITUTES THE LEGAL CEILING ON THE CHARGE TO BE IMPOSED ON THE IMPORTED PRODUCT, MAY VARY FROM ONE CASE TO ANOTHER, PARTICULARLY BY REASON OF THE NUMBER OF TRANSACTIONS TO WHICH VARIOUS DIFFERENT TYPES OF A PARTICULAR PRODUCT ARE SUBJECT UP TO THE TIME WHEN THEY ARE DELIVERED TO THE FINAL CONSUMER .
IN THESE CIRCUMSTANCES THE POWER MADE AVAILABLE BY ARTICLE 97 PERMITS THE STATES CONCERNED TO TAX AN IMPORTED PRODUCT AT A SINGLE RATE DEEMED TO CORRESPOND TO THE AGGREGATE TAX BURDEN BORNE BY DOMESTIC PRODUCTS .
12 IN ORDER TO ENABLE THE NATIONAL COURT TO DECIDE WHETHER THE CASE BEFORE IT IS GOVERNED BY ARTICLE 97, IT IS ONLY NECESSARY FOR IT TO BE IN POSITION TO DECIDE, ON THE ONE HAND, WHETHER THE SAID CASE INVOLVES A TURNOVER TAX CALCULATED ON A CUMULATIVE MULTI-STAGE TAX SYSTEM AND, ON THE OTHER HAND, WHETHER THE MEMBER STATE HAS ACTUALLY EXERCISED THE POWER MADE AVAILABLE TO IT BY THE SAID ARTICLE .
IF THE NATIONAL COURT CAN ESTABLISH THE EXISTENCE OF THESE TWO FACTORS, IT MERELY REMAINS FOR THE COMMISSION AND THE OTHER MEMBER STATES TO PUT INTO OPERATION THE MACHINERY PROVIDED FOR THEM BY THE SECOND PARAGRAPH OF ARTICLE 97 AND BY ARTICLES 169, 170 AND 173, TO REVIEW THE LEGALITY OF THE MEASURES ADOPTED OR TO HAVE IT REVIEWED .
IF, IN A PARTICULAR CASE, IT APPEARED POSSIBLE THAT THERE WERE AN INFRINGEMENT OF ARTICLE 97, SINCE NATIONAL COURTS ARE DEPRIVED OF SUCH POWER OF REVIEW, IT WOULD BE THE RESPONSIBILITY OF THE COMMISSION, UNDER THE SYSTEM INSTITUTED BY THE TREATY, TO ENSURE WITH EVEN GREATER VIGILANCE THE PROTECTION OF PERSONS CONCERNED .
14 IT IS, THEREFORE, SOLELY FOR THE PURPOSE OF ENABLING THE NATIONAL