Solid Energy is scoring its miners on such things as their work conduct and qualifications as it decides whose jobs will be cut at its Huntly East operation.
Some 63 jobs are to go at the mine in Waikato and more than 250 at Spring Creek on the West Coast following a downturn in the global price of coal.
On Thursday, more than 150 workers waited for letters outlining their future employment at Huntly East.
Solid Energy has a panel of four assessing workers to decide who will stay. Spokesperson Vicki Blyth says the state-owned company has had constructive engagement with the union in the decision process.
Some miners have received a letter, but others are still waiting.
The Engineering, Printing and Manufacturing Union says those who are selected for redundancy will get a week's leave and have until 12 October to challenge the decision before it is finalised.
Solid Energy says it is a very stressful time for everyone at Huntly East, but changes need to be made to ensure the financial viability of the mine.
Nick Korfage started at the Huntly East mine in February this year and has received his letter. He says his score was 159 points - 12 under the cut-off mark - which means he might lose his job.
Mr Korfage told Radio New Zealand's Checkpoint programme he does not know if he will dispute the score, but feels let down by the outcome.
He says the mining industry in Australia is not looking great, and if he stays in New Zealand he will be competing with experienced miners which won't be easy.
The fate of workers at Spring Creek mine will be decided later in October when Solid Energy finalises plans to mothball operations there.