Anti-TPP campaigner Jane Kelsey is aghast that Helen Clark supports New Zealand's involvement in Trans Pacific Partnership.

The former Prime Minister believes it would be unthinkable for New Zealand, as an export-oriented, small trading nation, not to be part of the agreement.

 "Of course New Zealand has to be in on the action with the TPP and go for the very best deal it can, as the agreement expands beyond the original four economies to a wider, regional agreement."

Professor Kelsey said Miss Clark's statement suggests she had become too far removed from the realities and opinions of ordinary New Zealanders.

She's calling on the former PM to heed the advice of the UN experts appointed to advise her.

Miss Clark and John Key have had a chat in New York about the issue.

Helen Clark endorsed John Key's push for a Trans Pacific Partnership Trade deal - and he, in turn, said he'll do all he can to help her become UN Secretary General should she decide to run for the position, and would lobby on her behalf with some of the influential leaders he knows and plays golf with. 

Mr Key has indicated any animosity is buried in the past.

"She texts me from time to time, I see her when she is in New Zealand usually, you know the kind of adversarial nature that you have when you leave the opposition Prime Minister that sort of evaporates over time and for the greater good."