National has ruled out doing a deal with The Opportunities Party (TOP) in Ōhāriu.
At the weekend Newshub obtained a letter TOP leader Gareth Morgan planned to send voters in the electorate, wide open with the retirement of United Future's Peter Dunne.
"You have the power to determine the future direction of the Government in New Zealand and lay to rest the ghost of a man who has, for too long, warped our democracy in his own interests", the letter read.
"With your two votes you can get three local MPs. Cast your party vote for the party you like best... If you vote for... Jessica Hammond Doube she gets into Parliament and takes as many as five other TOP MPs with her."
Dr Morgan's hope is that TOP gets enough MPs to replace Winston Peters and New Zealand First as king-maker following the election.
But National leader Bill English has turned down the offer.
"We've got a good candidate there. He's running hard and we want to win that seat," he told The AM Show on Monday.
National has long backed Mr Dunne, who's seat has given the National-led Government an extra seat in Parliament. But he won't extend the same courtesy to TOP, perhaps expecting them to side with Labour.
"He's got a bunch of ideas, but they're not focused on the big choice for New Zealand, which [is] actually between the big parties."
A tweet by Labour general secretary Andrew Kirton at the weekend suggests they're not keen either.
"No thanks Gazza. Two ticks @nzlabour in Ōhāriu, and everywhere," he wrote.
Mr Dunne decided to leave politics after polls showed he was well behind Mr O'Connor.
Dr Morgan has said he'll fold TOP if Labour adopts its policies.