The fate of West Coast miners will be learnt on Thursday when workers collect redundancy letters from employer Solid Energy.
The state-owned coal company confirmed on 28 June that 185 people will lose their jobs at the Stockton mine near Westport.
The Engineering, Printing and Manufacturing Union's West Coast organiser Garth Elliot said notices have gone up around the workplace on Wednesday, directing staff to collect letters from the company's Westport office from 10am on Thursday.
Mr Elliot said 102 wage workers and 33 salary employees are affected, and understands that significant numbers would take voluntary redundancy.