The Port Chalmers branch of Maritime Union of New Zealand has been headquartered in the 73-year-old brick Waterfront Industry Commission since its inception and fought the demolition, but the organisation was evicted about three weeks ago.
Demolition of the building's roof and upper walls is under way and expected to take up to eight weeks.
Port Otago has maintained the non-heritage building was asbestos-ridden and required earthquake strengthening, and the best option was to demolish it.
Following rising public interest, Maritime Union of New Zealand Port Chalmers branch secretary Phil Adams was contacted yesterday and said he would "definitely back saving of the facade".
Port Otago was not able to respond to the suggestion yesterday.
Mr Adams said "Morale is at an all time low ... people are feeling we won't have any heritage left the way we're going."
Mr Adams said there was "a lot of ill will" at Port Chalmers at present, from both the community and retired, former Port Otago staff, over the building's demolition.
"My phone has been running hot and there's plenty of ill-feeling on social media," he said.
On Wednesday this week two Port Chalmers residents made submissions to the Otago Regional Council, questioning Port Otago's performance on several fronts, including ship noise, saving the studio of the late artist Ralph Hotere on Observation Point, and also the demolition of the union building.
Retention of the facade would be a "win-win" for Port Chalmers residents and Port Otago, one submitter said.
Port Otago's owner, the Otago Regional Council, last month declined the union's plea to let it make its case at a public forum.
