Police have warned media that disclosing unlawfully intercepted private communications could land journalists in jail for two years.
Phil Goff, on the campaign trail in Auckland this morning, said the entire saga had become a "farce".
"I'm sure the police have more important things to do than get involved in a political spat between the National Party and the Herald on Sunday," he said.
It had become a criminal matter because John Key was refusing to be transparent, Mr Goff said.
There needed to be media ethics around private conversations, but the public understood that the meeting between Key and John Banks over a cup of tea had been a political stunt, he said.
The freelance cameraman who recorded the conversation, Bradley Ambrose, maintains it was recorded accidentally.
Mr Ambrose gave the recording to the Herald on Sunday, who then sought Mr Key's consent to publish it, but it was refused.
Interviewed on TV3's Firstline this morning, Mr Key told presenter Rachel Smalley he has nothing to hide.
"I have a totally clear conscience over what I have done, I think it is the Herald on Sunday and the cameraman who may not have a clear conscience.
"And in the end they will have to answer to the police.
"I don't care about what is on the tapes."
Mr Key said he would not release the tape "on principle".
"Once you say 'you've got to release it because someone wants you to', then I'm telling you now, today it's me, tomorrow it could be you."
He maintained the recording was "News of the World tactics", referring to the phone hacking undertaken by the British tabloid.
"I find quite abhorrent the actions of News of the World."
The News of the World was shut in August following the scandal, which including the hacking of the phone voice messages of Milly Dowler, who was abducted and killed in 2002.
When Ms Smalley said hacking into the phone of a dead girl was very different to the so-called "tea-tape", Mr Key interrupted "no it's not".
"No it's not - it's an illegal attempt to get information."
Mr Key said the public do not believe he has anything to hide by not agreeing to allow the recording to be released.
"They know as I know the Herald on Sunday would simply have printed it [had there been anything explosive]," he said.
"What they do know is it is likely to have been pretty bland."
Ms Smalley, who admitted to My Key she was privy to the tape's contents, proceeded to ask him who historically has supported Winston Peters and why he believes the party is losing support.
Mr Key said New Zealand First's voters were "older New Zealanders", Mr Peters was "not a terribly stable politician" and not being in Parliament had not helped Mr Peters' party.
Ms Smalley also asked Mr Key whether he wanted Act leader Don Brash to be part of any future coalition with National, and whether he would prefer to work with Mr Banks or Dr Brash.
"It doesn't work like that - it would be the Act Party. The point here is, at the end of the day, the Act Party and their representation is a matter for their members."
