Mondelez International has denied it banned Cadbury workers from speaking publicly about the closure of the Dunedin factory.
Workers told reporters they were not allowed to speak to them, and the New Zealand Herald reported on a leaked briefing pack that told staff not to speak to media.
The packs were handed out on Thursday when staff were told of the proposed closure.
The company said yesterday there had been "no media ban implemented in response to yesterday’s proposal announcement" but workers were subject to the company’s "standard" media policy.
"During such a difficult time, it’s important our people don’t feel pressured to respond to media inquiries and many have expressed that they aren’t comfortable being approached by the media."
E Tu union vowed to fight the "media ban", and would defend any worker who breached it.
E Tu food industry co-ordinator Chas Muir said the workers were devastated and should be able to talk about what had happened.
"We will challenge any disciplinary action taken against workers by Mondelez who speak to the media.
"This is a muzzling of distressed people in a community which needs to debate what has happened to its fourth-biggest employer.
"Mondelez appears to have a global strategy of slashing costs and jobs to bolster shareholder returns regardless of the consequences to communities, and this strategy needs to be challenged," Mr Muir said.
E Tu has close to 100% membership among workers on the site.
