Conservative Party leader Colin Craig is challenging New Zealand First's Winston Peters to stand against him in East Coast Bays, saying he should come clean on his intentions.
Mr Peters has criticised Mr Craig for trying to do a deal with the National Party over the seat, and hinted at the possibility he might stand there himself.
Mr Craig said Mr Peters could learn from the Conservatives and be upfront about this intentions.
"We've been very open and transparent. We're not sneaky about what we're up to. We say 'here's where we're standing, and this is our bottom line,'" he said.
"I wish that Winston Peters would have the integrity to do the same. If he wants to stand in East Coast Bays, why doesn't he say so."
Mr Peters' comment means its possible he, long-serving electorate MP and Foreign Minister Murray McCully and Mr Craig could all stand in the seat.
Prime Minister John Key on Monday told Radio New Zealand's Morning Report programme that National was close to announcing its intentions regarding Mr Craig.
"What I can say is it's highly likely we'll make an announcement next week on what we're doing," he said.
Mr Peters at the weekend dismissed Mr Craig as a shooting star but attendees at the Conservative's conference had confidence in their man.
"I'd like to say Colin could take him out because I think Colin appeals to a lot of constituents in that sector. A lot of those conservative values, which he's now promoting," one woman said.
Mr Peters on Monday said his party would decide in the next few weeks whether he would stand in the electorate.
He said deals, such as the one forged in Epsom between National and ACT at the last election, were an abomination.
"It's a disgrace with respect to the manipulation of democracy in our country, and it's bringing politics into even more odour," he said.
"We'll decide in the next few weeks where we're going to stand, and what the campaign will be with respect to that."
But Mr Key said deals were simply a feature of MMP.
"MMP's an environment that requires coalitions, we all accept that. I think a bit of advanced debate about that is not actually unhelpful and I think voters probably appreciate that."