The New Zealanders languishing in Australian detention centres are a stone in the shoe of the first John Key-Malcolm Turnbull meeting this weekend, but there are face-saving ways Turnbull could cut Kiwis some slack

When Malcolm Turnbull touches down in New Zealand tomorrow night for his first visit as Australian Prime Minister, there will be much back-slapping and bonhomie between two very similar politicians. But far from what the men would have expected just a few weeks ago, the mutual appreciation society will be over-shadowed by the detention centre issue.

Though they won't admit it, both leaders have been blind-sided by an issue that risks doing genuine, if temporary, harm to one of the closes bi-lateral relationships in the world. We share much history and under CER, our economies, labour markets and travel arrangements are incredibly closely aligned. Yet on the question of how to deal with New Zealand citizens who have committed crimes across the Tasman, Australia seems determined to treat us no differently from any other country.

Around 200 Kiwis are now in Australian detention centres due to past offending, with 40 on Christmas Island. And the numbers are growing. Some estimates suggest as many as 5000 New Zealanders could be sent home by the new Australian law introduced at the end of last year that means foreigners who have committed crimes worthy of at least a year in prison are to be deported.

What's often not reported about that one year figure, is that it's cumulative. So it doesn't have to be a crime serious enough to warrant a sentence of a year or more; it could be a series of more minor crimes (six months, four months and two months, for example) that add up to a year. Hence how mere shoplifters are getting caught up in this Aussie purge.

And, of course, it includes New Zealanders who have lived in Australia almost all their lives. You'd think that a country that forms you from infancy might take some responsibility for a person's offending, but – ironically given Australia's history –  our neighbour is showing no pity for even some petty criminals. The stance by Australia's Immigration Minister Peter Dutton has given Turnbull little wriggle room. Consider this quote made on Sky TV just a few weeks ago:

"We have the ability to cancel visas if people are here doing the wrong thing, if they're committing offences in our society. We don't have a tolerance for that, and that's the way in which the law operates, and it will continue into the future".

Turnbull and Key are cut from a similar cloth – both extremely rich men on the centre-right of politics, with burning ambitions yet a determinedly flexible approach to politics (although Turnbull arguably less so on that latter point). Turnbull chose Key as a foreign leader he especially admired when elevated to the top job (don't forget the pair share the same image managers in Crosby Textor), and suggested he wanted to be Key-like in his pragmatic (read: poll-driven and embracing of the centre) approach to leadership.

In private discussions will be convivial and politically pragmatic; it will be the talk of men used to doing deals.

But the public talk will be harder to manage, because the public expectation in both countries is very different. New Zealanders can't understand why Australians would treat us this shabbily – where is the ANZAC spirit now? – while Australians are inclined to think 'good riddance to bad rubbish'.

Continuing his run of recent missteps, Key misread the tone on this one at first. He gave it his usual shrug for a second, before realising many New Zealanders felt a sense of injustice for friends and family in Australia, and the death of Junior Togatuki. So he has strengthened his language, suggesting Australia gets a lot from our close ties and it should "take the rough with the smooth".

He's been honest, though, that in private his tone will be quite different. He was surprisingly frank about his strategy with Turnbull on TV3's The Nation a couple of weeks ago:

"You've got to be a bit careful. We don't want to, sort of, force Malcolm Turnbull into a corner where he has to, sort of, pick and choose. You've got to give political leaders a chance if they're going to make nuanced changes to policies to do so in a way where they can preserve their dignity but maybe cut you a bit more space."

So how could Australia change its policy and still save face? Two possibilities stand out in my mind. First, the threshold for deportation could be lifted for New Zealanders. Until the law change last year it required a two year sentence to be deported, so perhaps New Zealanders could get a "carve out" that put us in a special category that applied the previous threshold. After all, it's not as if Australia was awash with minor Kiwi crims until last year.

That may not be the tough line Turnbull wants to present domestically, but in reality it would be rational and a relatively minor change. The bikers and serious New Zealand criminals Australia wants gone would still be sent packing.

Alternatively, New Zealanders could await deportation in the community rather than in Australia's horrendous detention centres. That leaves a particularly bad taste over here, especially when people are being plucked from their families and detained there over crimes that happened years ago. Where's the justice in re-interring people who have already done the time?

Australia hasn't resourced this law change well enough and I'm told there's a serious backlog in the allocation of cases; these Kiwis could be detained for months awaiting a case manager to figure out how to process and deport them. That's a huge cost to Australia and an unnecessary one. Why not just leave them where they are, in the community as they await deportation?

What's the downside? That they're a flight risk? That they could abscond to... er... New Zealand? Well, that would only do Australia's work for it. It seems possible New Zealand could make the case for more humane treatment for our citizens.

Now that would be a very Key-like move.