The Trans Pacific Partnership will be signed today, but that won't be the end of it.

Trade representatives from 12 countries are in Auckland to sign the controversial agreement.

New Zealand Herald Business editor Liam Dann told Rachel Smalley each country will then need to get the deal through their Parliament.

LISTEN ABOVE: Liam Dann speaks to Rachel Smalley 

"America is the big one, because if America can't get it through their domestic politics then it's not quite going to be the deal that we all thought our hoped it would be."

Reuters' David Lawder said the earliest it could be submitted to the US Congress is within 60 days, but that's unlikely, given the strong opposition.

Mitch McConnell, who is the Republican leader of the US Senate told Obama that he has problems with the TPP agreement, and that he would like to see it delayed until later this year - after the Presidential election."

Neighbouring Canada's trade minister will be signing the TPP agreement today - but there's doubt over the commitment of her government to the deal.

The TPP was largely negotiated under the former conservative government.

CBC News Janyce McGregor said the new liberal government is far more cautious of the deal.

"Some of this is politics, some of this is also just the sense that perhaps there wasn't a lot of public consultation or information available about this deal."

In Australia, a more than 300,000 strong petition against the trade deal has been handed into Parliament.

Australian Trade Minister Andrew Robb is in New Zealand to sign it, along with other international trade ministers from around the world.

Australian correspondent Donna Demaio said a large alliance of 59 groups including World Vision, The Public Health Association, unions, Greenpeace, Catholic leaders and The Fair Trade and Investment Network have also handed a letter to Parliament:

"They really want an independent assessment of the impacts and repercussions of this partnership."

Trade delegates in Auckland today are likely to be left in no doubt as to the divided opinions surrounding the free trade deal.

MORE: TPP protesters say they are making a point, not causing trouble

A large number of protestors are expected to gather outside Auckland's Sky City where the deal is being signed at 11.30 this morning.

While in the Auckland CBD last night, reporter Michael Sergel said a large billboard sponsored by US, Canadian, and Kiwi NGOs, was displaying anti-TPP messages directed at trade ministers.

"It's a massive sign, it's really difficult not to see. It's been directed at the trade representatives here in Auckland for the signing."