Vernon Tava's Sustainable New Zealand is about to hit the 500 member mark necessary to register as a political party.

In February, Tava revealed his business-friendly but environmentally-focussed party, promising he was open to working with either National or Labour.

He has now revealed to The AM Show that the party is close to having 500 members - which is required to officially become a political party.

"We are so close, so close I can taste it," he said.

Tava - who founded the party and is the unofficial leader - says many "exciting people" are involved and it has substantial financial backing.

"You have got to have supporters, you have got to have money. There are a lot of people who are supportive of the party. The support is out there in terms of people, in terms of expertise.

"The thing I hear more than anything else is 'Finally. We have been waiting for this to happen'."

He says while the party is focussed on the list vote - with 5 percent necessary to enter Parliament without holding a seat - it's likely candidates will also be stood in electorates.

"The list vote is what it is all about, but I do think that you do have to stand candidates in electorates as well because the electorates where you stand candidates is where you tend to get stronger party votes."