To listen to some of the more hysterical predictions, New Year's Day will see Dover thronging with Bulgarians and Romanians climbing off the ferries to look for work in Britain.
Heathrow will be working round the clock to land all the planes coming in from Sofia and Bucharest. By the end of the month, even the Poles and Czechs will be complaining about immigrants taking their jobs.
From the start of 2014 restrictions on the free movement of Romanians and Bulgarians within the EU will be lifted. In response, according to some reports, the government is pushing for a 75,000 annual cap on the number of EU migrants who can come to Britain every year. But that would be a huge mistake.
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In reality, mass migration from the rest of Europe is a trump card for the British economy. And we don't have so many of those that we can afford to throw any of them away.
There are plenty of predictions being thrown around, but no one really has any idea how many people will come from the two EU states. When the doors were opened to the other new eastern European nations a decade ago, the government estimated only a few thousand would come. It turned out to be more than a million.
And it's no longer just eastern European countries that workers are moving from. The next wave of mass migration may be from the crisis-hit nations of the eurozone. The latest figures show a big jump in young migrants from Italy, Spain, and Greece.
The numbers coming from Spain rose by 40% to 49,800 in the year to September, according to the Department for Work & Pensions. The numbers from Italy increased by 52% to 39,400; from Portugal by 45% to 28,300; and from Greece by 31% to 9,300.
That could be far more significant. These are big countries, with well over 100 million people between them (compared with 27 million for Romania and Bulgaria). With little hope of returning to growth and job creation while they are locked into the single currency, more and more are likely to come to Britain.
The government is running scared. It is hard to see how a 75,000 limit on migrants from the EU can possibly be legal under European law. If the EU is no longer about the free movement of goods and people, then it no longer has much purpose. But it is, of course, understandable.
Mass migration places a strain on public services and infrastructure. It is unpopular among low-skilled workers, whose jobs are threatened and whose wages are undercut.
Yet both migration and a rising population are a powerful driver of economic growth. One day perhaps the textbooks will have a few examples in them of countries that managed to combine a declining population and a growing economy, but so far there haven't been any.
The only major country with a declining population right now is Japan, and we all know how successful it has been over the last two decades. Once the population starts to fall, so does the number of workers.
Too few are left to support the growing numbers of pensioners, and increasingly geriatric societies lose their appetite for risk and innovation. Government deficits swell out of control as tax revenues go down and spending on healthcare soars. Growth evaporates.
But immigration is keeping Britain's demographics healthy. According to Migration Watch, a pressure group, Britain's population will grow to 70 million by 2027, and 73 million by 2037, from its current level of 63 million. That is a big increase. If the stream of Spanish and Italian migrants turns into a flood and they are joined by young French workers, the actual numbers may be even higher.
The UK will be almost alone among European countries in seeing its population grow significantly. Only France has similar robust demographics. Within two decades, Britain will have overtaken Germany as Europe's largest country.
But it is not just Europe we will be growing against. The Korean population will start declining in 2018. Taiwan's population will be going down by the 2020s. From 2016, even China's working-age population will start to decline.
Fast forward ten or 15 years, and Britain will be one of the few countries in the world, apart from a few African nations, with a rising population. All of our major competitors, apart from France and the US, will be grappling with falling populations, and all the problems that come with that. But the numbers of people living and working here will still be rising.
A young, ambitious population is a major source of economic strength. Britain doesn't have the best education, or the best infrastructure, or the lowest tax rates. But if we can keep attracting lots of hard-working young people from the rest of Europe, that will be a huge boost to growth. The UK can limit migration from the EU if it wants to but the price will be a high one.
