With Labour, the Greens, and Act lined up to oppose any animal testing of synthetic highs, Prime Minister John Key had little option but to change his mind and rule out such tests outright. It was that, or risk a humiliating defeat in what has already been a hellish couple of weeks.
Mr Key says the Government still supports limited animal testing for medicines that could be used to save human lives. However, it was not appropriate for recreational drugs.
Yet only last week, he went along with animal testing of recreational drugs if it occurred on foreign animals, and at a pinch, on local rodents. But certainly it was no go with cuddly New Zealand bunnies or beagles.
At an ethical level, his reasoning was rather woolly. Even if it does appear to have some legislative backing. From the 2012 annual report of the National Animal Ethics Advisory Committee (NAEAC), we learn that under the Animal Welfare Act 1999, some animals do rank in the official mind as superior to others when it comes to "research, testing and teaching" (RTT).
The act, we're told "precludes the use of non-human hominids" - gorillas, chimps, bonobos or orang-utans - for RTT except with the approval of the Director-General of the Ministry for Primary Industries. Whatever the ethics, we do have a soft spot for our closest cousins in the animal world. That, or the bureaucrats took the Planet of the Apes movie to heart.
The hasty amendment to the Psychoactive Substances Act is expected to be passed under urgency today. It will not just outlaw the 36 or so "synthetic high" products that had provisional approval until the new testing regime was introduced, it also rules out animals being used as part of the testing process for any new "low-risk" products.
Mr Key concedes the ban on animal testing "is likely to restrict substantially the set of products that could actually be passed under the new regime", but putting a brave front on it, says "it would be no bad thing" if "none of these things re-emerge".
So much for National's brave, pioneering experiment in drug reform. One that had gained the attention of governments worldwide, all faced with the same problem.
For National, the problem of drugs, both organic and synthetic, will not go away, it will just retreat underground again. And in taking a hard line on animal testing as a key plank in his anti-drugs policy, Mr Key has rather painted himself into a corner when the Animal Welfare Amendment Act is reported back to Parliament in late June.
We're now told that National's new policy is to only support animal testing for drugs that could save human lives - and then only on a limited basis. If that's the case and animals, under National, will not be forced to test party pills and the like, what about cosmetics and household cleansers and similar products?
In August last year, when the bill passed its first reading under urgency, animal welfare groups were vocal in their criticism of its weaknesses. They highlighted cosmetic and party-pill testing in their criticism.
Animal welfare group Safe concedes it is unaware of any such testing occurring in New Zealand, but argues it is not prohibited, and that cosmetics and household products that have been tested overseas on animals are widely available here. That's not to say there is no animal experimentation here. Just the opposite.
According to the 2012 NAEAC annual report, a total of 301,964 animals were reported as "manipulated" in research, testing and teaching. Just over 10 per cent were used more than once. Despite Mr Key's soft spot for rabbits, I have to report that 95 per cent of the 1519 rabbits under-going RTT that year either "died or [were] euthanased". Only mice came off worse, with 99 per cent of the 55,870 used expiring.
Close behind were 2090 guinea pigs, 96 per cent of which died testing for animal vaccines. Then there were the nearly 28,000 fish, 32 per cent of which died "to validate a tool to accurately predict stress and mortality under a variety of fishing conditions".
Of course fishermen will argue that fish don't have feelings like you or me, just like crayfish don't feel a thing when they're dropped into a pot of boiling water. But with an election looming, is this a debate that Mr Key wants to open up?