An inadvertent recording captured Key's comments on NZ First, Act.
The secret "cup of tea" conversation between Prime Minister John Key and Act's John Banks has been captured on a recording given to the Herald on Sunday.
The recording, which was made unintentionally, according to the man who made it, contains fascinating insights into how Key thinks the next Parliament will shape up after the election.
We have chosen not to publish exact details of the conversation, as it was supposed to be in private, and Key last night refused to waive privacy considerations.
A spokesman for Key said: "The Prime Minister's Office is not giving permission to the Herald on Sunday because the conversation was recorded in a manner where neither party knew it was being taped."
The conversation was inadvertently recorded in Newmarket's Cafe Urban where Banks and Key had arranged to meet in front of 40 members of the media. The meeting was a platform for Key to symbolically endorse Banks in the Epsom seat.
If Banks, who has been trailing National's Paul Goldsmith in polls, wins the seat, it would give National a much-needed coalition partner. Banks initially told the NZ Herald on Friday he was not concerned about any recording. But when told the Herald on Sunday had a copy, he refused permission for it to be printed.
"I'm not saying yes. I'm not saying no. I think you need to talk to the Prime Minister. It was his cup of tea, he paid for it."
Herald on Sunday editor Bryce Johns said the newspaper had sought legal advice and believed it could have gone ahead, but it was an ethical matter for the newspaper. "Neither politician knew they were being recorded and they want to keep that chat private."
The freelance cameraman who made the recording, whom the paper has agreed not to name, said the recording had been made accidentally after he was stopped by Key's security staff from recovering the recording device. It transmitted the recording to the camera operator's equipment but he did not discover until later.
In the eight-minute and 26-second conversation, the pair discuss Act's future and its leadership, New Zealand First's electoral chances and the percentage of the vote the National Party would secure.
Labour's Epsom candidate David Parker said Banks and Key's actions were "hypocritical" after the pair organised and stage-managed the "cup of tea" scenario to get the public maximum impact.
"They have been hung on their own petard and they should be pressured to disclose what it is that is so distasteful they don't want the public to hear it."
Parker said the public did not have a right to all aspects of public figures' lives but the situation involving Banks and Key was different.
"They manipulated things. Because of a mistake caused by an agent of the Prime Minister not allowing this person to pick up his kit, they are uncovered. What is it that they are hiding?"
Two senior politicians to enjoy the "cup of tea" show of support were Act leader Don Brash and former party leader Rodney Hide. As National Party leader, Brash met United Future leader Peter Dunne in 2005.
Brash said he believed the it would be "unethical" to publish. "I suspect there is nothing terribly sensitive in it."
Hide, who met Key for coffee during the 2008 election campaign, said, "I'm of the strong view that private conversations should stay private."
University of Otago political scientist Dr Bryce Edwards said the information should be released. It was increasingly difficult for the public to access real information about politiciansbecause the media was outgunned by political budgets and press officers.
"It is a conversation that would help voters navigate the election campaign. In an election campaign, voters need maximum amounts of information and viewpoints. In the name of democracy, we need this sort of information."
Right-wing blogger David Farrar also supported release if the recording revealed hypocrisy. "If there is something which is contradicted by what they say publicly, it makes the public interest argument."