Long running talks to hammer out a free trade agreement between 11 Asia Pacific countries have resumed in Auckland, sparking criticism and protest.

Opponents of the Trans-Pacific Partnership (TPP) say the high level negotiations are undemocratic, and warn promised benefits will come at a cost.

"It's being held in secret," said Robert Reid of First union.

"I mean this is the umpteenth meeting that's happened and we still don't know what's in the agreement."

Watch the full story on TVNZ's website - click on the link below.

See also FIRST Union Retail Secretary Maxine Gay speaking on 3 News.