Member State's autonomy to regulate the acquisition of the full status of Member of the European Parliament.

Elected Members of the European Parliament are required under Spanish Law to oath to uphold the Constitution before the National Electoral Commission within five days from the announcement of the results. It is a suspensory condition of the effectiveness of parliamentary immunity. Its fulfilment differentiates between the elected member of Parliament and the full member of Parliament. This article examines how neither EU Law nor the Court of Justice have defined Member States' margin of autonomy to regulate the acquisition of the status of Member of the European Parliament. Likewise, the CJEU has commented on fundamental aspects of the procedure -the beginning of the mandate of the Member of the European Parliament, the extension of parliamentary immunity, the announcement of election results by national authorities and the verification of the credentials by the European Parliament- that enables us to delineate the distribution of responsibilities of the election process between national authorities and the European Parliament, from the announcement of the results to the entry into office of the Members of the European Parliament. In the end, the election process of the Members of the European Parliament is still mainly regulated by national provisions (ex art. 8 of the European Electoral Act).