Vernon Tava has officially announced his new centrist environmentally focussed party, Sustainable New Zealand.
The party promises to work with both National and Labour, unlike the Green Party, which has said any deal with the National Party is unlikely.
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"Instead of negotiating with both major parties, they have made a decision to always support the formation of a Labour Government meaning that Labour can take them for granted," the Sustainable NZ Party website says.
"This is no way to get the best deal for the environment."
Mr Tava first suggested the idea of a "blue-green" business friendly, environmentally focussed party in January.
National Party leader Simon Bridges said at the time he had not been involved in planning the party, but said it could be a good idea.
"I think in truth what you've got in the Green Party that's in Parliament is a party that's very much to the left of Labour - so that's not for everyone.
"I think the idea of a party in the middle that wasn't about all the left-wing stuff, if you like, but was about the environment and doing something with that, could be quite powerful."
But not everyone is on board.
"There's a chance this party might be worse for the National Party," says political commentator Bryce Edwards said in January.
"It might take votes away from the National Party, yet it may not get to 5 percent."
At the same time Mr Shaw defended his party's stance of not working with National.
"What they are saying is they want to be a party that works alongside the National Party," he told Newstalk ZB.
"People who vote for the Green Party have shown time and time again that their vast preference is for us to support Labour-led Governments."