I WROTE last week about the boat people from Europe’s refugee camps and their growing penetration of UK home waters, but I think I may have gone into print a bit too early.

Certainly the last seven days have seen no easing of the pressure on our fluid southernmost frontier – the English Channel – where 677 people have been caught on their attempted transit of the world’s busiest shipping lane.

In fact, the harder we batten down inside our territorial waters, the further the problem is likely to spread. The United Nations, no less, has warned us this might cause “fatal accidents”. The French have had to signal warnings to frigates of the Royal Navy not to chase the refugees’ pathetic dinghies back across the mutual maritime border. France is our ally, but one likely to be a stickler for its rights. What would the tabloid press say if a French warship sailed into our territorial waters?

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It may not be long before we are faced with a similar situation round Scotland too. If the criminal gangs said to be organising this traffic do their homework, they will soon discover there are other sea passages where the UK is porous. After Brexit has been completed, Northern Ireland will remain, in effect, a part of the European single market, which means EU citizens will be able to live and work there. What is to stop them travelling over here from the province freely, too?

So the practical flaws in our prospective Brexit deal start to reveal themselves. Nobody has ever told us much about them. Even if, in time, this particular transitional arrangement should change, those Ulster Europeans could still live and work in Donegal next door. From there the distance across the North Channel to the Scottish coast is only 90 miles, and on the Galloway side lie any number of quiet inlets, from the Annan to the Urr to the Stinchar, where illegal boats could unload human cargoes. I would not have thought the extra distance unduly daunting to migrants who might have already trekked from central Asia.

A plus is that these refugees would then be landing in a Scotland with a government that proclaims its sympathy for them, indeed points out how an increase in the local labour force is essential if economic growth is to be boosted. Deepening depression would certainly be a high price to pay for the sake of solidarity with prejudiced English people whose dislike of dusky foreigners outweighs any rational calculation of material advantage.

Of course, an independent Scotland could choose for itself whatever immigration policy was best for it. While we remain inside the UK, we have to have a common immigration policy supposed to suit all parts of it. But it is the central government, without necessarily listening to a word from elsewhere in the devolved structure, that has the job of defining the common policy.

We are regularly assured that, once it has been defined, no deviation will be allowed. This is apparently to remain the case even if such a deviation were of advantage in one or more of the four nations of the UK, and an effort was mounted to make something of it.

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We saw a consequence of the muddled thinking in this area of policy during the fuss over the boat people last weekend. “This is a very bad and stupid and dangerous and criminal thing to do,” said Boris Johnson of the migrants surfing their way across the Strait of Dover. The Home Secretary, a “furious” Priti Patel, was the one who backed sending in the Royal Navy to stem the human tide.

Yet neither these nor other Tory Ministers paused for a moment to note that the devolved administrations in the UK also, to say the least, take an interest in migration issues and that none of them has actually followed the UK government’s lead. In fact both Scotland and Wales have explicitly rejected its hostile approach, after spurning all consultation with them. Boris only retorts: “There is no such thing as a border between England and Scotland.”

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YET that, the traditional high Unionist answer, does not get the Prime Minister off the hook or even begin to give him what he desperately requires – a policy, or at least the beginnings of one, that is recognisably Conservative yet also geared to Scotland’s specific problems and needs.

Until this happens, I think he will continue in vain to send his ministerial underlings to butter us all up.

The typical case of the boat people shows us why. This Government is widely seen as the weakest in many decades, but I don’t think any of that matters a damn to Johnson, who is uninterested in policy, except insofar as it produces headlines and tame interviews. Only if it feels important to him will he make any effort to master a brief. Immigration is without doubt one of the few subjects that will prompt him to do so. All his colleagues in the Cabinet will then agree with him. Or at least they will go round the country, from one microphone or camera to another, saying they do.

If they cannot manage this, they are clueless in utterance. Look at how mealy-mouthed they became while Boris himself lay in hospital struck down with the coronavirus. Not a new thought gained admission to the ill-stocked minds of his closest colleagues.

This is why they cannot deal with Scotland. It would not surprise me to learn they are unaware the Scottish Government has a different immigration policy from theirs, because understanding of such complexity would be beyond them.

To them, if central government follows an anti-immigrant policy then nobody else can be reckless enough to adopt a pro-immigrant policy. It would be not only disloyal but also foolish, given how the central government has a majority of 80 at Westminster. So the fact that lesser governments inside the UK may dissent is an irrelevance to be ignored. All this makes a mockery of the Westminster chatter and scribblings that have reached our ears and eyes over the past week or two, of the idea that Boris’s interest might be won for a new political culture embracing certain federal concepts.

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The main one is that in the UK the central government and the lesser levels of government might come to share sovereignty in some sense, in place of the present system of absolute sovereignty for those the Queen has called to exercise it in her name in Parliament.

It sounds as if it might be quite nice, but I think it so far beyond the bounds of present possibility that it can be ignored, at least so long as Boris leads his government. When he won the General Election last December, he saw himself as the Prime Minister of Brexit. Instead, whether he likes it or not, he is destined to become the Prime Minister of coronavirus.

Now, as a man who seems to embody the very opposite of what Scots seek from their leaders, his main struggle may well turn out to be saving the Union from himself.