Justice Minister Andrew Little says a decision from the Advertising Standards Authority about an advertisement from National MP Nick Smith could have a chilling effect on democracy.
But Smith has hit back, calling Little arrogant, a bully, and an opponent of free speech and legitimate debate.
The ASA dismissed a complaint by Little, the Minister for Pike River Recovery, about an opinion article - labelled as an advertisement - by Smith in the Nelson Weekly newspaper about the Pike River re-entry.
The ASA decision, released this afternoon, is the latest in a saga that includes claims and counter-claims about the truth, threats and phone calls, and a late-night visit from police.
Smith's article referred to criticism from mining journalist Gerry Morris about the Government's intention to bypass mine safety regulations for the Pike River re-entry.
Morris had written an article containing his concerns for the Greymouth Star on August 21, which prompted Little to call Morris' article "erroneous and misleading" during Question Time.
In his statement to the ASA, Morris said he had been offended by Little's comments in the House and had called Labour MP Greg O'Connor to confirm Little's home address as he wanted to write to Little directly.
He has previously told Stuff that he had made threatening comments to O'Connor about Little, but regretted using such strong language and only wanted to send him a letter.
"Police visited my home late on the night of Friday August  at 10.35pm," Morris said in his ASA statement.
"My partner was shocked and distraught to be in her nightwear confronted by armed police. They said they were the Wellington CIB responding to a complaint by Mr Little. I was quickly able to satisfy police that I posed no risk to him."
Smith weighs in
Smith's advertisement, which he pays the Nelson Weekly to publish, outlined this series of events and prompted the ASA complaint by Little.
The complaint was threefold: it was misleading to say the Government was seeking an exemption from worksafe safety laws, inaccurate to say those laws required two exits from a mine, and untrue to say that Little had laid a complaint to police.
The ASA threw out Little's complaint - the first two parts unanimously and the third by majority - and said that Smith had provided "sufficient substantiation" in the context of "advocacy advertising".
Little called it a "ridiculous" ruling that could have a chilling effect on democracy.
"I'm surprised a complaint about statements that clearly weren't factual statements have been regarded by the ASA as acceptable.
"The concerning thing is, a year out from the next general election where there will be political advertisements ... if we can't have the ASA upholding a standard that means you can't lie or state things that are factually untrue, then that is very disturbing for our democracy.
"Unfortunately the ASA has now held itself up as an authority that is prepared to tolerate lies in advertising."
Little said he had not laid a police complaint, but the ASA had dismissed his complaint because Smith had been told that he had laid a complaint.
"A threat about me was made to Greg O'Connor. He told my office, and my office notified Parliamentary Service.
"That was the last contact anybody in my office had to do with it. Parliamentary Service and police decide how they deal with that."
Smith said Little's contempt for the ASA decision was telling.
"How can he continue to claim that matters are untrue when an independent authority has said that my statements were true?"
He said Little's complaint was part of a pattern of behaviour to bully and silence legitimate criticism.
"Saying the independent authority is wrong shows an extreme level of arrogance from a Minister who is meant to be protecting free speech and is the Minister in charge of fair elections."