Prime Minister John Key says he will promote the merits of the TPP free trade agreement on the lower marae at Waitangi and that overall it was an important debate for his Government to win.

"The opportunities that come from a trade deal like TPP are at the core of what we are about as a Government, which is international connectedness and greater opportunities for our people," he told the Herald last night.

Mr Key will head to Waitangi on February 5, the day after the 12-country trade deal is signed in Auckland, with protests promised by opponents, including Auckland University law professor Jane Kelsey, who believes it will severely reduce New Zealand's sovereignty.

The Ministry of Foreign Affairs and Trade and Trade Minister Todd McClay will also embark on roadshows for the public - which are almost certain to attract protests.

Advertisement

But Mr Key believes most people have a limited understanding of the deal.

"I suspect the people who are vehemently opposed are, broadly speaking, opposed to free trade agreements because the arguments they have put up have been proven to be incorrect. It doesn't matter how many times we say Jane Kelsey is actually wrong, in the end she doesn't want to believe she is wrong, and the people that follow her don't want to believe that."

An elder from Te Tii Marae, Kingi Taurua, has said Mr Key would not be welcome on February 5 after the signing.

Mr Key said every free trade deal New Zealand had signed had been of net benefit to New Zealand, as TPP would be.

Most people would see that New Zealand was going to do well out of an FTA that better linked a country of 4.5 million with hundreds of millions of income-consumers.

New Zealand already has trade agreements with six of the 11 other countries in the TPP.

It effectively means new FTAs with the US, Japan, Canada, Mexico and Peru.

After several days of criticism by Maori about the TPP, Mr McClay yesterday released a detailed written response, setting out the clauses in the agreement on the Treaty of Waitangi - effectively allowing the Government to positively discriminate in favour of Maori.

He said the value of the Maori asset base was now over $40 billion and oriented towards the export economy.