Green Party co-leadership contender James Shaw has faced calls of "join us" from National MPs and has been praised by former Act leader Rodney Hide.
Part of his co-leadership pitch is a promise to reach those who considered voting Green in the last election but ultimately went with National.
But the former management consultant says those who peg him as a "Blue Green" open to helping National form a government have it wrong.
Mr Shaw said he wanted to work more closely on strategy and tactics with Labour to ensure voters saw both parties as able to form a credible alternative government come 2017.
"If we are going to do that, Labour also needs to make that choice. But my sense is they kind of learned the lesson from the last election as well."
He will face off against MPs Kevin Hague and Gareth Hughes and Auckland lawyer Vernon Tava for the position Russel Norman will vacate next month.
Mr Shaw has frequently spoken of research showing the high number of voters who considered voting Green at the last election but did not, including those who went with National.
That and his corporate business background have led to some suggesting he could be open to the Greens advancing their agenda from within a future National government.
Mr Hide wrote in his Herald on Sunday column yesterday that electing Mr Shaw would open up the possibility of supporting National, while a vote for Mr Hague would ensure "they will stay glued to Labour".
It is evidently an endorsement Mr Shaw doesn't want. "Frankly, he's just making things up ... People have this idea that if you are a business person you must by default be a National Party supporter."
In a debate on TV3's The Nation, Mr Tava called for the Greens to be neither left nor right, and able to work across the political spectrum.
All other candidates supported the current direction from members that a Green-National coalition was "highly unlikely", with Mr Hughes saying such a union was "unfathomable", partly because of issues such as child poverty.
Mr Hague said he had worked with the National Government on issues and would be happy to continue doing so; however, he would not like to see the Greens enter such a coalition.
Mr Shaw told the Herald he believed most Kiwi voters still had a first-past-the-post mentality.
That did not mean the voters who considered the Greens but ultimately went with National were unreachable under his commitment to a partnership with Labour.
"There are a lot of people out there who are really pissed off about National's record on the environment, who would like to vote for us but didn't feel that we were yet credible enough," he said.
As for the praise from those on the right, Mr Shaw believes right-wingers often have another motive.
"They have been doing this thing in the House for a while of like, 'Come and join us - you know you're a Blue Green, you're one of us.'
"I said to [a National MP], 'Look, can you stop this, you are just killing me.' And he said, 'We know, why do you think we're doing it?'"
Last night, Mr Hide said Mr Shaw was in a difficult position in that many members were on the hard left.
"He has said he wants to target middle New Zealand and broaden the Green appeal. I was just explaining for him what that would mean."