Toby Manhire: Brace for the post-vote Brexodus

Our shores 'like England in 50s' may prove lure to pro-leavers.

I vote no more referendums, or at least no more this year. The New Zealand flag vote of 2016 was blighted by rancour, animosity and name-calling - which, I argued at the time, was at least in part down to the fact that we were debating the overhaul of a nation-state's symbol in isolation from the core constitutional substance that should underpin any such change.

Over in Britain, meanwhile, the polls are about to close in their referendum on whether or not to remain a part of the European Union. Now there's a subject of core constitutional substance. And how did that pan out? Rancour, animosity, name-calling, and much worse. If New Zealand's flag vote witnessed a spate of face-pulling, pushing and shoving, the Brexit leadup has at times resembled a crazed, drunken brawl. Whatever today's outcome, the hangover will be lasting.

British Prime Minister David Cameron pledged an an in/out vote on the EU ahead of the last election to mollify a vociferous Eurosceptic faction of Conservative MPs. He'd have been confident that a referendum, were it to happen at all, would return a conclusive result for the status quo. As the campaign rolled on, however, and the malevolent electoral gravity dragged both sides towards messages of fear - for Leave, it was fear of immigration, for Remain, fear of economic doom - it became clear that it could go either way.

The tenor of the campaign is best encapsulated by the attempts on both sides to invoke the world's most evil people to make their case. "Leave" figurehead Boris Johnson, the Tory MP and former London mayor, whose fluffy mop of blonde hair and practised air of befuddlement disguises a potent political ambition, declared that the European Union was attempting to create a mighty superstate, much like, you know, Adolf Hitler. A few days later, Johnson's political stablemate and referendum opponent, Cameron - the two were school pals at Eton, and are pictured together in that famous picture of Oxford's ineffably posh Bullingdon Club - remarked that a vote to leave the EU would probably be just what Isis would want. Not to be outdone, the other senior Tory Exiter, Michael Gove, this week compared economists supporting Remain to scientists working for Hitler.

And yet all three of them - Johnson, Cameron and Gove - have proved comfortably less outrageous, scaremongering and odious than Nigel Farage, the leader of the UK Independence Party, who produced a billboard with the words "Breaking Point", showing, in what some saw as an echo of Nazi propaganda, a queue of refugees winding into Slovenia, and has pressed every available xenophobic button, playing to Britons' basest fears. Farage is Britain's answer to what some have called a "Trumpian post-truth politics", which harnesses the fear and anxiety produced by deregulation and globalisation, channelling a largely illusory idea of the Good Old Days - the nostalgic utopia before the liberals and the immigrants and the feminists and the politically correct pointy heads stormed the citadel.

In general terms, the EU would hardly be predisposed to agree to be friends with benefits after a break-up.

While both sides can be reasonably accused of overstating the impact of going the other's way, the consequences of an exit could be seismic. There is the immediate economic effect: to the chagrin of Mr Gove and co, pretty much every economist and economic organisation predicts it would have a detrimental impact on Britain's currency, on the financial sector and on trade. (Boris Johnson has promised to apologise on television if all that happens, which is nice.)

Beyond that, the near certainty that a majority of Scots will support Remain would trigger in the case of an overall UK vote to Leave a clamour for another vote on independence from the Union. Scotland would seek to rejoin the EU as a standalone state, though that would be far from a sure thing, given that countries facing their own separatist movements, such as Spain, may be reluctant to permit such a precedent.

As for a post-EU Britain, the Leave camp argue that a free-trade deal can be done, and a status akin to that of Switzerland or Norway secured. The reality, however, is there is zero chance the EU would agree to freedom of trade without freedom of labour (as is the case for Norway), so the immigration situation would be unaffected. In general terms, the EU would hardly be predisposed to agree to be friends with benefits after a break-up: that would only encourage others to consider similar.

Most troubling of all is the possibility, over time, that the EU begins to unravel altogether, with perhaps Greece, Portugal and others falling away. Even at an outside chance, that's something to worry about. After all, for all its bursts of bureaucratic daftness, the Union's great achievement is that its members don't war with each any more.

At this point it is obligatory to ask What Would it Mean for New Zealand, and the answer, probably, is not a great deal. It would be annoying in terms of trade agreements; it might very well make it easier for New Zealanders to gain work visas, something Boris Johnson, a very likely PM should the Leavers prevail, has supported before. It would make Britain less attractive to many of us who love the place in large part for the emergence of its modern, outward-looking European-ness. (And, hell, for what it's worth, my guess is the vote will go 53-47 for Remain, but Cameron will still be gone by Christmas.)

But there's another answer, in the spirit of post-truth politics, and it is that whichever way they vote, there will be a Brexodus: a flood of miserable Britons attempting to seek asylum in our South Pacific idyll. A vote to leave will see thousands of young liberal families descend upon us, clamouring for the schools, hospitals and craft beer. A vote to remain will trigger a mass escape from the older, more conservative, mostly English folk (if polling is a guide). They're the ones prone to say that New Zealand is like England in the 50s, after visiting parts of New Zealand that are like New Zealand in the 50s.

Let's agree to tell them only the unpleasant things about this place. Such as the fact they'll almost certainly have to live in a stationwagon for the first year. The streets are riven with warfare between rival avocado-smuggling gangs. Personal gardens are illegal. Richie McCaw has retired. There's no train to France.

And if the Brexodus does transpire, you know what we have to do. Build a wall. And make them pay for it.