An Australian campervan company that puts controversial slogans on its vehicles has been threatened with prosecution and a fine of up to $20,000.
The Whangarei District Council is also threatening to wake up Wicked Campers' clients in their vans to tell them to cover up the offensive words.
The Advertising Standards Authority (ASA) has made numerous rulings against Wicked Campers, and has expressed disappointment at its refusal to respect the principles of self-regulation.
Slogans such as "Fat chicks are harder to kidnap" have incurred the wrath of Women's Refuge NZ and Equal Employment Opportunities Commissioner Jackie Blue.
And this month, a slogan proclaiming, "My boss told me I was a w***er, I was so surprised I almost let go of his c***", prompted a Whangarei resident to complain to local MP Shane Reti.
Dr Reti, who in turn complained to the council, says its threat of legal action alleging a breach of its signage bylaws is an important development - and he wants other councils to take note.
"We have another tool that we can bring to this fight, to enforce on this company that they have to adhere to New Zealand standards," the MP said.
"This is the first time they face prosecution. I'm commending Whangarei District Council for showing leadership on this and for actually utilising their signage policy."
Dr Reti said Wicked Campers had failed to respond to his calls and emails.
The council emailed Wicked Campers after getting legal advice that it could seek a court injunction or prosecute for a bylaw breach, which carries a maximum penalty of $20,000.
Its email said: "You may like to consider what actions you can take to reduce the likelihood of council taking action.
"Separate to the above, it could include asking your clients to tape over certain words. This may result in your clients being woken during the night if the matter comes to our attention."
Dr Reti said the Personalised Plates numberplate company had confirmed to him that it would not allow the offensive words featured in the slogans.
The MP pointed out that two of them are on the Broadcasting Standards Authority's list of unacceptable words.
"I understand 'edgy' - it may not be my preference, but I understand it - but this is clearly offensive."
Lonely Planet dropped Wicked Campers from its Australian and New Zealand guidebooks following a 120,000-strong petition against the company's slogans. That protest led to the removal of some slogans.
Wicked Campers could not be reached for comment.
Last April, it released a statement that joked it had employed monkeys to monitor the messages on its vans.
"[They are] a team of highly intelligent, socially conscious super monkeys to closely monitor the subject matter featured on our vehicles and scream loudly when offended."
Previously, the company had said that anyone offended should just paint over messages they didn't like, but its statement said it would prosecute any who did so.