It's not perfect but it's good enough, Prime Jacinda Ardern said today in defence of the revised TPP trade deal against an attack from the Green Party.

After 10 years in the planning, negotiating, stalling and renegotiating, the revised deal will be signed by 11 countries in Santiago, Chile, by Trade Minister David Parker who, along with Ardern, joined anti-TPP protests when it was first signed in Auckland in 2016.

But Green MP Golriz Ghahraman addressed a protest rally of about 100 at Parliament today saying that the Government was indulging in "spin" to sell their switch in position.

"It has been devastating to watch as the coalition parties have done such a complete turnaround, and have used what has essentially been spin to justify their turnaround on what is essentially the exact same agreement."


Ardern is finishing up her week-long tour of the Pacific in the Cook Islands but told reporters when she had marched against it, it had been on the basis of wanting to protect the ability to regulate the housing market from offshore speculators "and that is what we have done".

"We haven't quite got the perfect deal but we made enough changes that we could be satisfied to support it," she said.

The deal is not the same as was signed by 12 countries in Auckland because 22 provisions that were negotiated by the United States have been suspended in the wake of its withdrawal from the agreement.

They will be subject to renegotiation should the US ever apply to rejoin.

The Labour New Zealand First Coalition also changed two other provisions late last year after forming the Government: reducing the circumstance under which investor-state dispute settlement clauses could be triggered, and introducing a mechanism into the Overseas Investment Act to ban sales of existing housing stock to foreign based speculators.

It also changed the formal name to Comprehensive and Progressive Agreement for Trans Pacific Partnership.

National trade spokesman and former minister Todd McClay who helped to keep the deal alive after the withdrawal of the US said New Zealand exporters could rejoice in Parker and New Zealand First leader Winston Peters hanging up their protest signs.

He also said it was fundamentally the same deal that was signed in Auckland and an important deal.

It increased access to millions of consumers around the world in markets including Japan, Mexico, and Canada.

He acknowledged the work over 10 years of "world-class trade officials", in particular former chief negotiator David Walker and current chief negotiator Vangelis Vitalis.

"It is good that Labour and New Zealand First have finally decided to act in New Zealand's best interests in spite of their fierce opposition to the deal when it was negotiated under National."

The deal won't enter into force until at least half of the party countries ratify it. Members are Singapore, Brunei, New Zealand, Chile, Australia, Vietnam, Peru, Malaysia, Japan, Canada and Mexico.

The Ministry of Foreign Affairs and Trade last month released a national interest analysis of the deal. It estimated that it would boost New Zealand's economy by $1.2 billion to $4 billion a year once fully implemented.

"That's a significant increase in a country where 620,000 jobs are dependent on exports," Parker said at the time.

At the same time, New Zealand's right to regulate in the public interest, including in such areas as health, education and the environment, were protected.