UPDATED 3.53pm The Prime Minister's now hopeful rather than confident that the Trans Pacific Partnership will pass thorough the American political process.

Presidential candidates Hillary Clinton and Donald Trump are both opposed to the TPP, and it isn't clear that current President Barack Obama has the support in Congress to seal the deal.

John Key said if it doesn't get through, a lot of different issues arise.

"Do we go back to the drawing board? How does that all work, what time frame? It depends on who the President is and what they want to do."

Proponents, including the Prime Minister, hope it could be pushed through during the lame duck period.

That's after the Presidential election in November and before the new leader's sworn in in January.

"President Obama himself has been making comments at the G20, still standing up for why TPP should take place and putting up the case that it can go through during that time period."

"So I'd be hesitant to use the word confident, but I'm certainly hopeful."

TPP opponent Jane Kelsey said while it's clear the TPP has hit hurdles in the US, with both Presidential nominees opposed to it, there also seems to be a lot of intentional "talking down" of its prospects.

"To get the opponents to back off in thinking it's not longer an issue. Immediately after the election we are expecting a big surge from Obama to try and get the votes through in what's known as the lame duck period."

Meanwhile Mr Key doesn't see his constant criticism of the Clark Government, and his support for Helen Clark to lead the United Nations as contradictory.

The Prime Minister heads off to New York the week after next, where he'll again push Miss Clark's case to become the next UN Secretary-General.

"I think she's got - at a personal level - lots of skills, and brings those to the job. I don't agree with her prescription for New Zealand, and that was why we stood against her and campaigned to change the government. I have no regrets about that."