A stoush between the Meat Workers Union and AFFCO Talleys over what the union can say about the company online is heading to the Employment Court.
The meat company wanted the union to stop posting what it described as "unbalanced, misleading, untruthful and/or derogatory" comments, which breached the duty of good faith, it said.
The posts were published on Twitter and a union-managed website, jobsthatcount.com.
There were 32 tweets that AFFCO complained about, including several about Talleys Group owner and managing director Sir Peter Talley.
The union said the claims against it were "frivolous" and should be thrown out.
However, the Employment Relations Authority ruled the Employment Court should hear the matter.
The tweets listed in the authority's ruling (PDF, 250KB) include:
Hey Talleys. You don't need workers to bow to your every command. Threats and bullying when workers speak out won't stop them. #SirTalley— Darien Fenton (@DarienFenton) June 19, 2015
Lots of calls coming in frm AFFCO Talley workers underpaid & ripped off by Talleys in 1st pay since court win. #getyourshittogethertalleys— Jobs that Count (@jobsthatcount) December 8, 2015
The Talley madness continues. Three workers at Rangiuru AFFCO suspended for wearing their nice green union shirts. #getagripTalleys— Darien Fenton (@DarienFenton) December 17, 2015
Meat Workers Union organiser Darien Fenton said if AFFCO was successful it would have a chilling effect, as it would effectively gag the union from campaigning.
"We've had 18 months of hell for workers," she said.
"Workers and delegates have been locked out and sacked, bargaining has broken down, it's an ongoing series of problems that never seem to get anywhere ... you can't say let's all be nice about it when the company doesn't come to the relationship with clean hands."
The union was always careful when commenting online, Ms Fenton said.
The authority did not make a ruling on the nature of the posts, but found there was justification for the Employment Court to settle the matter.
"Publications about Sir Peter Talley and his knighthood might be publications that undermine his position," the decision said.
"They might also, in some cases, be seen as publications which, as he is someone who is seen as an owner of AFFCO or at least influential in the management of AFFCO, might undermine AFFCO's position vis-à-vis its employees or even undermine its position in relation to ongoing collective bargaining."
There are similar proceedings before the Employment Court about what statements the union could make in the media.