The very idea sounds not so much outrageous as heretical. Keeping at least one cat is seen as a Kiwi birthright. But Morgan wants that to change. And his eponymous foundation has employed researchers to do some number-crunching that tells a sobering story.
New Zealand's 1.6 million households are home to 1.4 million cats. Cats bring home 13 pieces of prey a year, but that's only one in five of their kill. Do the arithmetic.
The real psycho killers are feral cats, but their populations are descended from abandoned or lost domestic cats. And both varieties share the same bloodlust; cats are the only animals that kill exclusively for pleasure, the campaign says.
Morgan says he's ready for the opprobrium that will be heaped upon him, but he's not advocating wholesale extermination.
"I am not suggesting people bop their pets on the head," he says.
"But a responsible cat owner will have the cat neutered, microchipped and keep it indoors. And when the cat dies I think people should consider not replacing it."
The "make this cat your last" proposal is not, in fact, as serious as it gets. Essentially, Morgan is looking for a withdrawal of the social permission that has been granted to cats, much in the same way as it was withdrawn, in the space of less than a generation, for smokers.
We would agree to agree that straying cats are destructive trespassers and trapping them is a socially responsible act that should be encouraged. That calls for leadership from local and central government: "If a cat comes on to my property," says Morgan, "I can trap it - these aren't gin traps, after all; they're humane cages - and take it to the council. If it's chipped, the owner gets fined. If it's not chipped, the cat is euthanased."
If all that sounds drastic, Morgan wants you to consider the alternative.
"New Zealand's unique ecology is a massive asset," he says.
"It's not just because we love hugging trees or seeing tui flying by. The more polluted the world becomes, the more valuable a place like this becomes because of its ecological assets. For me as an economist, the question is how can we capitalise on it.
"If you foster this asset it will be a place that talent wants to come and live and talent makes income and jobs."
The argument about how pure "100 per cent Pure" really is aside, this country has invested and continues to invest millions in re-establishing native bird populations. Eco-sanctuaries like Zealandia in Wellington and Maungatautari near Cambridge are testaments to a deep-seated belief that the dawn chorus that deafened Joseph Banks on the Endeavour ("the most melodious wild musick I have ever heard," he called it, "the most tuneable silver sound imaginable") should not be allowed to fall silent. Morgan's unimpressed.
"These eco-sanctuaries are nothing less than the most expensive cat food factories in the world. What the hell is the point in having all of these conservation projects, in pissing private and public money into these things, if the birds fly out of them and get slaughtered."
Morgan flew to China on Monday night to a family wedding. He chuckled when I suggested this would be a good week to be out of the country.
"I'll be back for round two," he says cheerily. "I've got another angle on all this once I see how round one goes."
Debate on this article is now closed.</i>