"There will be chanting and that kind of thing because we've got a message to get out there. But it'll be fun, it'll be a nice day out."
The Green Party said Kiwis were being sold a "dud" and there was too much secrecy around the TPPA.
"Information about the agreement has been made public only through leaks, despite repeated calls by New Zealanders to make the details public," said Green Party trade spokesman James Shaw.
"If the Government is so confident this deal is beneficial to New Zealand they should release the full cost-benefit analysis," he said.
"We aren't being told what benefits this deal will bring us... We know through leaks that the TPPA is a Bill of Rights for multi- national corporations."
Mr Shaw said the deal put the interests of major corporations ahead of New Zealanders' health, environmental and democratic rights.
"Make no mistake, this is a corporate power grab on a scale never before seen in human history," said Todd Rippon, Actors Equity New Zealand vice-president.
"This treaty is so repugnant that if a full text of the negotiations were released to the public tomorrow it would cease to exist by the end of the week because anyone with a brain and a gag reflex would reject it outright."