Ever since its origin in the early 1920s, open registry shipping has been the subject of much debate in international, governmental and industrial shipping circles. The first opposition came from labour unions in traditional maritime countries, whose members' jobs were threatened by the transfer of ships to Liberia, Panama and other open registry countries. Later, shipowners from a number of European countries persuaded their governments to take action against the unfair competition which in their opinion was presented by open registries. In the 1970s, developing countries called for them to be phased out, as they felt that the existence of open registries hampered the development of their merchant fleets.