Mana leader Hone Harawira said it was a "wasted exercise" and "pointless".
"We've spent $100 million dollars already to lose two yacht races. While we've been doing that, we've had more than a quarter of a million children in this country living in poverty, every single year for the last 10 years."
Act leader Jamie Whyte said a Government grant amounted to compulsory financial support for a private event.
"I don't think people should be forced to support the America's Cup."
The Government has signalled it would likely provide more money to Team NZ, if re-elected.
It has already provided $5 million to help keep Team NZ afloat while it decided whether to amount another challenge.
The decision, in June, to challenge again was accompanied by a deal for private sponsorship, understood to be worth $10 million. The announcement was made as Team NZ chief executive Grant Dalton faced questions over his annual salary of about $2 million during the last challenge.
The Government contributed $36 million to Team NZ's last campaign, which ended in an 8-9 loss to Oracle in the closest America's Cup in history. An independent evaluation released in March this year showed a positive impact of $87 million on the New Zealand economy.
Economic Development Minister Steven Joyce said the Government would see a business proposal from Team NZ after the venues for the next regatta were decided.
"We'll assess that at the time. It's not expected to be decided before the election.
"A re-elected National Government would make a decision on whether to provide further funding to Team NZ and how much based on the economic benefit it would bring to New Zealand, and in particular to our exporters."
IN THE HOT SEAT
John Key, National
David Cunliffe, Labour
Russel Norman and Metiria Turei, Greens
Hone Harawira and Laila Harre, Internet-Mana
Colin Craig, Conservatives
Jamie Whyte, Act
Peter Dunne, United Future
Te Ururoa Flavell, Maori Party
