Although the Greens polling is around the dangerous five per cent threshold, Shaw said it was needed to provide an option for Labour other than NZ First: "With the Greens you get a government of change, with NZ First you get a government of chance."
Maori Party co-leader Marama Fox said she would find it difficult to work with Peters because of his views on the Treaty of Waitangi and getting rid of the Maori seats.
She also appeared to have all but written off National's chances of getting back into Government, saying it was clear there was a mood for change and the Maori Party would prefer to work alongside the Greens in a Labour coalition rather than NZ First.
Act leader David Seymour also appeared to cast doubt on National's ability to win at one point, saying New Zealand was on the cusp of putting Labour leader Jacinda Ardern into government because it lacked vision.
"We are on the brink of electing a light-weight as Prime Minister and National have no one to blame but themselves. National have looked down on vision ... and it's because they don't have a vision that they are now losing votes to a new leader selling a fake one."
There was further debate controversy after TOP leader Gareth Morgan unsuccessfully challenged TVNZ's decision to exclude him because his party had not polled higher than three per cent in its polls.
However, the new United Future leader Damian Light was allowed into the debate because the party had a representative in Parliament - Peter Dunne who has pulled out of standing again.
New UF leader Damien Light said it was a misconception that United Future was all about Peter Dunne.
"Here we are, a new fresh face, maybe this is going to be the Jacinda effect, maybe this is the Damien Light effect."
He was confident he would get to five per cent, saying United Future was the only party that offered long term thinking 10-20 years into the future rather than "knee jerk" policies.
Although Fox said she was willing to work with Labour, she also admitted she did not completely trust them. If Labour went ahead with water charges it would end up in the courts with Maori testing their rights.
She was wary of a repeat of Labour trying to legislate away the right to test those rights as it had with the Foreshore and Seabed Act.
Seymour said that water issue was a "tinder box" and tradeable quotas and rights were needed, which included recognising Maori interests, as happened with fisheries.
Asked what they would push for hardest in a coalition, Shaw said in the first 100 days the target of a net zero emissions by 2050 should be passed into law.
He said he was certain farmers would not go broke under the Greens' plan, the detail of which would be released on Sunday.
Seymour said he wanted teachers to get performance pay and looser resource consent rules in the cities.
Fox said child poverty would be key for her party - including moving towards the living wage.
Light said UF would not support any government that wanted to scrap the RMA.