Organiser Kirstin Miller said Bunnings told affected staff last week it was considering redundancies, at which time First Union requested the consultation period was suspended until the new year.
Miller said its request was denied, but staff staff weren't expecting to learn yesterday the stores would be closed in four days.
"It totally came out of the blue. That's one of the worst things about it," she said.
Miller said staff were told there was work for them until late January - possibly packing up the stores - but it was not clear yet whether they would be made redundant, or moved.
"The problem is there's not really any nearby stores for these workers to be easily redeployed to. So there's issues around whether they'd be willing to move, or whether Bunnings would give them compensation for travel."
She said one worker at the Te Aroha store had already been redeployed earlier this year from the Paeroa Bunnings when that closed due to flood damage.
Another worker employed at the Waikanae store for two years told the union they were shocked and angry at the closure, because staff had lives and friendships there, and the store was doing a roaring trade.
Bunnings New Zealand human resources director Jacqui Coombes said yesterday the closures followed a review of its "smaller-format Bunnings stores" in the country.
The two stores had been "challenged" to offer the full range and desired, "despite the excellent efforts of our team, best service", she said.
"Smaller-format stores are often in sites that are older and aren't able to offer the environment we will accept for both our team and customers."
All team members would remain employed into the new year to assist with closing the stores, and the company would work with each team member on options to suit their individual circumstances including roles in other stores.
"This is a sad and difficult decision and our first priority is to take care of our team members who will all have the choice to remain a part of the Bunnings team," said Coombes.
Kāpiti Coast district councillor Rob McCann said closing stores at such short notice was acting without care for the community.
"Employees at the Kāpiti cheese factory were at least given six months to find new employment," he said.
"Four days notice over Christmas is unacceptable. It's my hope that any further decision from the company takes into account the workers and their families."
