[1] The union established branches at Broken Hill, Roan Antelope, Mufulira, Nkana and Nchanga, however it struggled to recruit members, and by 1939 membership had fallen to 1,000 out of 2,500 eligible European mineworkers.
The main priorities of the union in its early years was to increase its membership and restrict the supply of labour to the mining companies in order to strengthen the bargaining position of the miners.
This second objective was threatened by the abundant supply of cheap labour from the local African population.
In order to counteract this the union adopted a principle of 'equal pay for equal work', meaning that no Africans would be employed for less than an equivalent European employee.
[1] In March 1940 NRWU launched a strike, which trigged a separate protest movement amongst African workers.