However the expert paper said the Treaty of Waitangi exception was seriously limited. It said the Government must agree that something is a Maori or Tiriti obligation, but responses to Waitangi Tribunal claims relating to the seabed and foreshore and water were examples of where it had refused to do so.
"The Treaty exception is limited in scope and relies on the good will of the Government to protect Maori rights," the report says.
Mr Taurua said he agreed with the statement and said while the Government had an obligation under the Treaty to protect Maori, they do not.
"Why did they not do that by engaging Maori in the TPP. It's just words, words and more words," said Mr Taurua.
But Mr McClay was adamant that nothing in TPP would prevent the Crown from meeting its obligations to Maori.
"The value of the Maori asset base is now over $40 billion, with significant ownership in key export sectors such as red meat, dairy, kiwifruit, forestry, and seafood. Maori therefore stand to benefit from the tariff savings under TPP on current exports across these sectors, which are estimated to be more than $200 million a year once the tariff commitments are fully phased in," Mr McClay said.