Grand Duchy of Luxembourg v European Parliament.
Date: 1983-02-10
16 THE FIRST PARAGRAPH OF ARTICLE 38 OF THE ECSC TREATY PROVIDES THAT ' ' THE COURT MAY , ON APPLICATION BY A MEMBER STATE OR THE HIGH AUTHORITY , DECLARE AN ACT OF THE ASSEMBLY OR OF THE COUNCIL TO BE VOID . ' '  THE POWER OF A MEMBER STATE TO BRING AN ACTION BEFORE THE COURT AGAINST MEASURES OF THE PARLIAMENT RELATING TO THAT TREATY IS NOT THEREFORE OPEN TO DOUBT . NEVERTHELESS THAT POWER IS RESTRICTED BY THE THIRD PARAGRAPH OF ARTICLE 38 OF THE ECSC TREATY TO GROUNDS BASED ON LACK OF COMPETENCE OR INFRINGEMENT OF AN ESSENTIAL PROCEDURAL REQUIREMENT .
19 SINCE THE SINGLE PARLIAMENT IS AN INSTITUTION COMMON TO THE THREE COMMUNITIES IT NECESSARILY ACTS IN THE FIELD OF THE THREE TREATIES INCLUDING THAT OF THE ECSC TREATY WHEN IT ADOPTS A RESOLUTION RELATING TO ITS OPERATION AS AN INSTITUTION AND THE ORGANIZATION OF ITS SECRETARIAT . IT FOLLOWS THAT THE JURISDICTION OF THE COURT AND THE PROCEEDINGS PROVIDED BY THE FIRST PARAGRAPH     OF ARTICLE 38 OF THE TREATY ARE APPLICABLE TO MEASURES SUCH AS THE CONTESTED RESOLUTION WHICH RELATE SIMULTANEOUSLY AND INDIVISIBLY TO THE SPHERES OF THE THREE TREATIES .
30 IN THAT RESPECT IT MUST BE OBSERVED THAT A DETERMINATION OF THE LEGAL EFFECT OF THE CONTESTED RESOLUTION IS INSEPARABLY ASSOCIATED WITH CONSIDERATION OF ITS CONTENT AND OBSERVANCE OF THE RULES ON COMPETENCE . IT IS THEREFORE NECESSARY TO PROCEED TO CONSIDERATION OF THE SUBSTANCE OF THE CASE .

SUBSTANCE
35 IN THAT RESPECT IT IS NECESSARY TO OBSERVE THAT ACCORDING TO ARTICLE 77 OF THE ECSC TREATY AND ALSO OF ARTICLE 216 OF THE EEC TREATY AND ARTICLE 189 OF THE EAEC TREATY IT IS FOR THE GOVERNMENTS OF THE MEMBER STATES TO DETERMINE THE SEAT OF THE INSTITUTIONS . IN GIVING THE MEMBER STATES POWER TO DETERMINE THE SEAT THOSE PROVISIONS MAKE THEM RESPONSIBLE FOR SUPPLEMENTING IN THAT RESPECT THE SYSTEM OF INSTITUTIONAL PROVISIONS PROVIDED FOR BY THE TREATIES IN ORDER THUS TO ENSURE THE WORKING OF THE COMMUNITIES . IT FOLLOWS THAT THE MEMBER STATES HAVE NOT ONLY THE RIGHT BUT ALSO THE DUTY TO EXERCISE THAT POWER .
37 IT MUST NEVERTHELESS BE EMPHASIZED THAT WHEN THE GOVERNMENTS OF THE MEMBER STATES MAKE PROVISIONAL DECISIONS THEY MUST IN ACCORDANCE WITH THE RULE IMPOSING ON MEMBER STATES AND THE COMMUNITY INSTITUTIONS MUTUAL DUTIES OF SINCERE COOPERATION , AS EMBODIED IN PARTICULAR IN ARTICLE 5 OF THE EEC TREATY , HAVE REGARD TO THE POWER OF THE PARLIAMENT TO DETERMINE ITS INTERNAL ORGANIZATION . THEY MUST ENSURE THAT SUCH DECISIONS DO NOT IMPEDE THE DUE FUNCTIONING OF THE PARLIAMENT .
38 FURTHERMORE THE PARLIAMENT IS AUTHORIZED , PURSUANT TO THE POWER TO DETERMINE ITS OWN INTERNAL ORGANIZATION GIVEN TO IT BY ARTICLE 25 OF THE ECSC TREATY , ARTICLE 142 OF THE EEC TREATY AND ARTICLE 112 OF THE EAEC TREATY , TO ADOPT APPROPRIATE MEASURES TO ENSURE THE DUE FUNCTIONING AND CONDUCT OF ITS PROCEEDINGS . HOWEVER , IN ACCORDANCE WITH THE ABOVE-MENTIONED MUTUAL DUTIES OF SINCERE COOPERATION , THE DECISIONS OF THE PARLIAMENT IN TURN MUST HAVE REGARD TO THE POWER OF THE GOVERNMENTS OF THE MEMBER STATES TO DETERMINE THE SEAT OF THE INSTITUTIONS AND TO THE PROVISIONAL DECISIONS TAKEN IN THE MEANTIME .
48 IN THAT RESPECT IT MUST BE OBSERVED THAT THE PRACTICE OF THE PARLIAMENT , DEVELOPED IN THE EXERCISE OF ITS INDEPENDENT POWERS , TO HOLD MEETINGS OF ITS COMMITTEES AND POLITICAL GROUPS IN BRUSSELS HAS NEVER BEEN CALLED IN QUESTION BY ANY MEMBER STATE .
54 IT FOLLOWS THAT IN THE ABSENCE OF A SEAT OR EVEN A SINGLE PLACE OF WORK , THE PARLIAMENT MUST BE IN A POSITION TO MAINTAIN IN THE VARIOUS PLACES OF WORK OUTSIDE THE PLACE WHERE ITS SECRETARIAT IS ESTABLISHED THE INFRASTRUCTURE ESSENTIAL FOR ENSURING THAT IT MAY FULFIL IN ALL THOSE PLACES THE TASKS WHICH ARE ENTRUSTED TO IT BY THE TREATIES . WITHIN THOSE LIMITS THE ESTABLISHMENT OF SUCH AN INFRASTRUCTURE OUTSIDE THE PLACE WHERE THE SECRETARIAT IS LOCATED MAY THEREFORE BE CONSIDERED COMPATIBLE WITH THE ABOVE-MENTIONED PRINCIPLES GOVERNING THE RESPECTIVE POWERS IN THE MATTER .
55 IT SHOULD NEVERTHELESS BE ADDED THAT THE TRANSFERS OF STAFF MUST NOT EXCEED THE LIMITS MENTIONED ABOVE SINCE ANY DECISION TO TRANSFER THE GENERAL SECRETARIAT OF THE PARLIAMENT OR THE OTHER DEPARTMENTS , WHOLLY OR PARTIALLY , DE JURE OR DE FACTO , WOULD CONSTITUTE A BREACH OF ARTICLE 4 OF THE DECISION OF 8 APRIL 1965 AND OF THE ASSURANCES WHICH THAT DECISION WAS INTENDED TO GIVE TO THE GRAND     DUCHY OF LUXEMBOURG PURSUANT TO ARTICLE 37 OF THE AFORESAID TREATY ESTABLISHING A SINGLE COUNCIL AND A SINGLE COMMISSION OF THE EUROPEAN COMMUNITIES .