In the 1950s, the Federal Republic of Germany introduced so-called low-wage groups. These wage groups applied to labour that was assumed to be physically less challenging and the predominantly female workers earned a lower salary than people in other wage groups did. While woman in this occupational groups had earned a lower salary before, the low-wage groups were introduced to adhere to the German Basic Law that prohibited the payment of unequal salaries for formally equal work. By introducing the concept of low-wage groups the labour in this wage group was formally declared different which served to justify the lower salaries. In 1988, metalworkers – among them many migrant workers – went on strike and sued against this discriminatory practice which resulted in the ban of low-wage groups by the Federal Labour Court.