UNLESS THE CONTRIBUTIONS COVERING ALL SUBSEQUENT MONTHS HAVE FIRST BEEN PAID ' ' , ARGUING THAT THE APPLICANT MUST START BY PAYING THE GERMAN CONTRIBUTIONS IN RESPECT OF THE PERIOD CORRESPONDING TO THAT IN WHICH HE WAS COMPULSORILY INSURED AND PAID CONTRIBUTIONS IN BELGIUM . IT IS THAT REQUIREMENT WHICH IS THE SUBJECT-MATTER OF THE MAIN ACTION . THE APPLICANT HAS AN INTEREST IN CHALLENGING IT OWING TO THE FACT THAT THE ' ' BUYING-IN ' ' OF RECENT MISSING PERIODS , IN THIS CASE FROM 1969 TO 1973 , IS MORE EXPENSIVE THAN THAT FOR PERIODS FURTHER BACK , NAMELY 45 MONTHS BETWEEN 1956 AND 1967 .
5 THE PARTIES TO THE MAIN ACTION ARE AGREED THAT THE APPLICANT DOES COME UNDER ARTICLE 49A ( 2 ) AND THAT THE REQUIREMENT LAID DOWN BY THE INSURANCE INSTITUTION OF PAYING FIRST THE CONTRIBUTIONS FOR THE PERIODS BETWEEN 1969 AND 1973 , NOTWITHSTANDING THE FACT THAT THEY CORRESPOND TO COMPULSORY INSURANCE PERIODS IN BELGIUM , DERIVES FROM A PROPER CONSTRUCTION OF THE RELEVANT PROVISIONS OF THE GERMAN LEGISLATION IN THE MATTER . THEY ARE AGREED THAT THE OBLIGATION UNDER GERMAN VOLUNTARY INSURANCE TO BUY-IN THE PERIODS CORRESPONDING TO INSURANCE PERIODS IN ANOTHER MEMBER STATE MAY BE IMPOSED ONLY ON GERMAN NATIONALS AND ON WORKERS FROM OTHER MEMBER STATES WHO LIVE IN THE FEDERAL REPUBLIC OF GERMANY AND THAT IT CANNOT BE IMPOSED ON WORKERS FROM OTHER MEMBER STATES LIVING OUTSIDE GERMANY .
6 ACCORDING TO THE DEFENDANT INSTITUTION THE CONFORMITY OF THAT REQUIREMENT WITH COMMUNITY LAW IS APPARENT FROM THE TEXT OF PARAGRAPHS 8 AND 9 OF PART C OF ANNEX V TO REGULATION NO 1408/71 OF THE COUNCIL . ON THE OTHER HAND THE PLAINTIFF IN THE MAIN ACTION CONTESTS THAT INTERPRETATION OF THOSE PROVISIONS . HE FURTHER MAINTAINS , AS HIS PRIMARY CONTENTION , THAT IF THE INTERPRETATION PUT FORWARD BY THE DEFENDANT WERE CORRECT , THE DISPUTED PROVISIONS WOULD CONSEQUENTLY BE TAINTED WITH DISCRIMINATION AND WOULD THEREFORE BE ILLEGAL OWING TO THE DIFFERENT TREATMENT IMPOSED ON GERMAN NATIONALS AND ON NATIONALS OF OTHER MEMBER STATES LIVING IN GERMANY BY COMPARISON WITH WORKERS FROM OTHER MEMBER STATES HAVING ACCESS TO THE GERMAN VOLUNTARY INSURANCE SCHEME AND TO THE ' ' BUYING-IN ' ' SCHEME , UPON WHOM SUCH AN OBLIGATION TO BUY-IN PERIODS CORRESPONDING TO A PERIOD OF INSURANCE IN ANOTHER MEMBER STATE CANNOT BE IMPOSED .
7 CONSEQUENTLY THE QUESTION REFERRED TO THE COURT PRIMARILY SEEKS TO DETERMINE WHETHER PARAGRAPHS 8 AND 9 OF PART C OF ANNEX V MUST INDEED BE CONSTRUED IN THE MANNER SUGGESTED BY THE DEFENDANT INSTITUTION AND , SECONDLY , SHOULD THE PROVISIONS IN QUESTION HAVE THAT EFFECT , WHETHER THEY ARE NOT THEREFORE INVALID BY REASON OF THE DIFFERENT TREATMENT OF TWO CATEGORIES OF WORKERS BOTH OF WHOM ARE ALLOWED ACCESS TO VOLUNTARY INSURANCE WITH THE OPTION OF MAKING BACK-PAYMENTS IN RESPECT OF EARLIER PERIODS .
8 THE PROVISIONS WHICH REQUIRE CONSIDERATION ARE ARTICLE 89 OF REGULATION NO 1408/71 AND PARAGRAPHS 8