More than 60 staff were called back from their holiday to be told their jobs at a South Waikato Sawmill were gone.
Pacific Pine Industries - a timber processing sawmill in Putaruru - announced on Monday they were going into voluntary administration and nearly everyone would be out of work.
The president of First Union says it was the worst possible timing for the workers.
Robert Reid said: "No notice, still on holidays, probably at the worst timing and worse outcome possible. This is a small community reliant on the forest industry and wood processing.
"It's the type of community that can't afford to have big job losses like that."
He said the union would work closely with Pacific Pines in an effort to help find its former employees new jobs.
Staff were told over the phone last Thursday and invited in for a meeting on 13 January for further explanations.
Reid heard one worker and his family had bought a house in the area over the holiday period.
The union will work closely with Pacific Pine's former workers to ensure they receive their entitlements and to help them find new jobs with a decent wage. Reid said while it was good news that there appeared to be some jobs in the area, "people who are made redundant or leave their particular jobs when there's a plant closure...often the new jobs are offered at much lower rates of pay".
Kenneth Brown, from receivers BDO, said Pacific Pine Industries had been making losses for the past two years. He said a shareholder injected a cash sum last year, but that did not help.
After a lengthy review the decision was made that the company would not continue trading, and, as the the plant was shut down and all wood processed before Christmas, it was not worth re-opening again in January.
Another wood-processing mill in the town, Carter Holt Harvey, closed its doors in 2008, causing 300 job losses.