Labour is calling on the Government to be more transparent about when the final sign-off of the Trans-Pacific Partnership is likely to occur.
A Chilean government spokesperson said the controversial free trade agreement would be signed off on February 4.
Duty minister Simon Bridges said many countries were not in a position to ratify the agreement, and no final date had been set.
But Labour leader Andrew Little said American officials have told him all signatories are also working towards the February 4 date.
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He said the New Zealand Government is in control of the text and the signing of it, and should not be keeping the date of the signing secret.
"I think the TPPA is going to be a major issue not just for New Zealand, but for the US and other countries that are party to it. People are entitled to know."
Mr Little said it would also be inappropriate to hold a signing ceremony for the deal two days before New Zealand's Waitangi Day.
"Our national day is a day that we celebrate our national identity and national sovereignty, and this is an agreement that potentially compromises our sovereignty."
Mr Bridges said the Government would announce the date as soon as the countries involved were in a position to do so.
"A number of countries are still working through their domestic approval processes required before signature."