A deal on the Trans Pacific Partnership (TPP) is still far from certain, University of Auckland law professor Jane Kelsey says.
Lawmakers in the United States voted yesterday to give President Barack Obama the negotiating power to resurrect the 12-nation TPP trade deal.
The so-called Trade Promotion Authority got through the House of Representatives by a narrow marking of 218 to 208 votes.
However, Ms Kelsey said some of the key features of the bill haven't been approved, which makes Senate approval far from certain.
She said a number of compromises had to be made to get the bill through the lower house, and politicians are going to have to move on key issues, related to wage and job protections, to see it though the Senate.
"The inclusion of the trade adjustment assistance package, as well as promises to vote to reauthorise the Export-Import Bank, were prerequisites for several of the 14 Democrat Senators who voted for the original fast-track bill in the Senate," she said.
Ms Kelsey added that Mr Obama also said he would not approve the fast-track process without the trade assistance package.
Professor Kelsey said TPP was unpopular with voters in the United States, even though it has the most to gain by the deal.
"The Senate process requires a 60-vote super-majority for the version of the fast-track bill approved by the House before it can bypass a filibuster and move to a formal vote.
"If just three of the original 14 Democrats withdraw their support from the fast-track law, the deal will not get to a vote in the Senate."
She said polticians were facing tight deadlines to finalise the deal, which is expected to be done by November when world leaders meet at the APEC summit in the Phillipines.