National Party leader John Key says he is backing senior MP Judith Collins 100 percent over her denial of a claim that her supporters approached New Zealand First with a possible post-election deal.
However, while campaigning in Gisborne today, Mr Key would not endorse her claim that New Zealand First leader Winston Peters is not telling the truth.
Mr Peters says an approach was made on behalf of an MP close to Ms Collins to see whether the leader could do a deal with her after the election on 20 September, if he couldn't do a deal with John Key.
Winston Peters said a person, whose identity he will not reveal, made the approach earlier this year, just before the Oravida scandal regarding a trip Ms Collins made to China blew up.
"There was no doubt in the clarity of the person's purpose and the link that was the case, and I'm astonished she is denying it, he told Radio New Zealand's Morning Report programme today.
Mr Peters said her supporters were planning to replace John Key. "That meant that there was serious instability being pointed to. The imputation clearly was they were so obsessed with power they were prepared to roll him as well".
Earlier this year, Judith Collins faced months of attacks over her dealings with export company Oravida, of which husband David Wong-Tung is a director.
Ms Collins said today that Winston Peters is the last person she would do a deal with or approach for anything and challenged him to front up with evidence backing his story. "I have never asked anyone to approach him, I have never approached him."
She said she despised Mr Peters's racist policies and his attacks on people based on their ethnicity. "This is the same man who, a few months ago, ridiculed my husband's surname in Parliament because he happened to have a Chinese grandfather and a Chinese surname. This is the last person I would ever approach."
John Key says he accepts Ms Collins' denial that her supporters approached Mr Peters. However, he says he could still work with the New Zealand First leader after the election.
"We work under MMP, and the reality of MMP is that it requires political parties to work together. In the end, New Zealanders will decide whether Mr Peters is back in Parliament, they'll decide whether National is in the strongest position to form a government."
Mr Key says there is a history of friction between some National MPs and Mr Peters, but the two parties have worked together in the past. He dismissed Mr Peters' comments as mischief-making. "There are going to be lots and lots of people making up nonsense rumours during this campaign because there's a bit of sport there."
Labour leader David Cunliffe won't say who he believes in the dispute - but says the public is now seeing splits within the National Party.
On current polling, New Zealand First could hold the balance of power between either a Labour or National government.