UPDATED 8.37pm The E tu union says boycotting Cadbury chocolate will only make things worse for those affected by the closure of the company's Dunedin factory.

LISTEN ABOVE: Dunedin North MP David Clark spoke to Larry Williams about the job losses from Cadbury's closure

The factory will be completely closed by early next year, and 350 people will be out of jobs.

Since the announcement was made last week, groups asking people to ditch the chocolate maker have appeared on social media.

Dunedin North's MP David Clark said it's unlikely Cadbury is going to make a U turn on its proposal to close down the factory.

He's met the workers set to lose their jobs.

Mr Clark told Larry Williams Cadbury's corporate objective is 6 to 7 percent growth internationally every year and to increase profit margin by at least 1 percent every year.

"They need to achieve scale and if that's what they're all about, simply shareholder value and not what individual community interests are, it's going to be a tough battle to get them to turn around."

E tu food industry spokesperson Chas Muir said a boycott will not help efforts to keep the factory open.

"They're talking about closing the place, we don't want to hurry them up in that enterprise, we want to contest it."

Labour Party leader Andrew Little spoke with E Tu Union delegates alongside Clare Curran and David Clark this morning.

One of those delegates, Donna Bouma, said today's a difficult day for the staff.

She said there will be lots of emotions for the workers, most of whom are returning to the factory for the first time since getting the news.

Ms Bouma said she found out an hour before the rest of the staff on Thursday morning.

Cadbury plans to move production to Australia.

A Dunedin dairy owner has vowed to boycott Cadbury products and called on other New Zealanders to do the same.