The Tariff Unity Act (“Tarifeinheitsgesetz“) provides that in case several collective bargaining agreements apply in one establishment, the agreement concluded with the union that has the highest number of members among the employees in the establishment shall prevail. Smaller unions also represented in the establishment are then only entitled to take on this same agreement for their members. The law was challenged by several trade unions. The ruling of the Federal Constitution Court, holding that the Tariff Unity Act is in line with the German constitution to a large extent, is a major setback for trade unions representing small but important key personnel within companies, such as pilots, air traffic controllers or train drivers.
Such unions will face significant limitations, e.g. regarding the right to initiate a strike, as long as there is another union represented in the establishment with a higher number of members. Companies will more often be in the position to deal with only one union and effectively rely on the peace duty once a collective bargaining agreement has been concluded.