Ralph Buckle is Director and Co-Founder of Commonwealth Exchange.

With the crisis in Calais keeping immigration firmly in the public’s mind, it is understandable that the Government might seek new ways to limit the numbers coming to the UK. However, whatever your view on the optimum level of immigration, the latest plans to kick out non-EU graduates of British Universities are probably the worst possible way to do this.

These students are, almost by definition, young, educated, integrated, and almost certain to speak English. Many are also independently wealthy, making them unlikely to ever require support from the taxpayer.

In particular, these students’ youth should not be underestimated. Britain has a rapidly ageing population. 63 per cent of the UK is now over 30 and the UK average age has now hit 40. Compare this to the Commonwealth and you see the reverse. 60 per cent of its population are under 30 years old, thereby offering a wealth of potential young students and workers. As our pensions liabilities become ever more unsustainable, we need fresh young talent to plug the gap.

There is also a concerning and growing shortfall of skilled graduates for a number of key industries, not least in engineering. James Dyson has made this point extremely well, so I will not repeat it ad nauseam. But suffice to say that Britain needs more highly skilled workers in almost every sector if we are going to continue to grow and finally improve our lagging productivity.

However, it is not just that we lose out on these potential workers by sending them home as soon as the cap and gown is removed. We also risk putting them off coming here to study at all. When we posted about these proposals on Commonwealth Exchange’s website, it took less than 20 minutes for a Canadian citizen with an Oxbridge offer to get in touch to say that he was now reconsidering.

This is mirrored in recent trends. Since the government began its tougher rhetoric on this issue, the number of foreign students has fallen by 25 per cent (December 2010- December 2014). Even more worryingly, this effect has been particularly noticeable amongst Commonwealth potential students. Their numbers have fallen a staggering 60 per cent.

This situation cannot be allowed to continue. Falling numbers of foreign students will damage our economy, our balance of trade, our universities, the education of domestic students, and our soft power.

Non-EU students currently contribute around £7 billion a year to the UK economy. Higher Education as a whole generates well in excess of £10 billion of export earnings for the UK. With our trade deficit becoming an increasing worry, we cannot afford to let this valuable source of income slip away to our international competitors.

But foreign students do not simply contribute to our economy. In addition, they effectively subsidise UK and EU students’ education by paying fees up to four times higher than their European classmates. And, at the same time, they can enrich the education of their fellow students by offering new and differing perspectives in seminars, often challenging orthodoxies and forcing others to consider viewpoints and thought processes that they might otherwise not have been exposed to.

Finally, by putting off non-EU students from studying here, or kicking them out as soon as they have finished their studies, we are seriously damaging our soft power. A recent study ranked Britain as the global leader in soft power. This is not to be sniffed at when our hard power resources are finding themselves ever more squeezed.

However, if you exclude the contribution of our education sector to this index, Britain falls to a lowly 15th, around the same level as Finland and Austria. As was reported at the time, our high ranking in education was “not because of [the UK’s] schools, which are fairly mediocre, but because its universities are second only to America’s, attracting vast numbers of foreign students.” We simply cannot afford to throw away this influential advantage.

In sum, graduates of British universities are exactly the sort of migrants that Britain should be seeking to attract, not kicking them out as soon as they compete their studies. The Government needs to rethink these proposals immediately as even the suggestion of them is damaging Britain in myriad ways. If they are implemented, it could take decades for us to recover.