Yasmin Alibhai-Brown : The talent that lies beyond the 'brightest and best'

Well I never. Tory immigration minister Damian Green announces more plans to keep out migrants, except for the "brightest and the best" – entrepreneurs, investors, ballet dancers, academics, other A-listers. The chosen ones will be fast-tracked. It is an interesting divergence from the original, universal immigration myth of the tired, wretched, ambitious and determined who go forth to seek freedom and opportunities.

In her captivating new book, The Mara Crossing, poet Ruth Padel reflects on this restlessness, shared by all living creatures: "We are all from somewhere else... we were wanderers once... the point of migration, whether you are a starling or a human being is to reach whatever helps you and your children live in a better place."

A substantial part of the British story is about these movements of the people. Think about America, Australia, New Zealand, Zimbabwe, South Africa, Kenya. As bad times hit, emigration is bound to increase. Some of the outward bound are skilled, others are not.

Two Tory activists recently told me that their children had decided to settle abroad – one in India ( he's married to an Indian woman) and the other, who did disastrously at university, in the Emirates. His devoted mum is sure: "He is just what they need. He's been quite clever, turned himself into a consultant and you know how disorganised Arabs are." Neither of the adventurous young men speak any of the local languages. Doesn't matter. They live by different rules.

Hyperactive anti-immigration campaigners presumably would see these chaps as the spirited descendents of the old Empire builders. Commoners from the old Eastern Bloc and old Commonwealth, on the other hand, are only ever a problem, bring interminable problems, ruin the country, must be deported or kept out. Some are indeed blackguards and scroungers, a minority. The rest are maligned for no good reason. Note that North Americans, Antipodeans and Caucasians from Africa are not subjected to ceaseless hostility, a long tradition on these isles going back to the age of exploration. Most other groups that have come to stay go through a baptism of fire. They've been victims of riots and killings and of dishonourable politicians and populist resentment.

Here is a challenge. Tell me if there's been any period since the 16th century when there was no hue and cry about "floods" of immigrants or "aliens" threatening the national identity. I am duly grateful and love London, my city. But the sheen of tolerance can't hide the indisputable facts. This is the worst and best of countries for a migrant. Some of us are here because you were there; others come because they have to flee, or because they know that in spite of all the hardships, they can flower in this multifarious nation.

A new exhibition on migration and British art opens this week at the Tate. It features some of the greatest artists of foreign birth or heritage, including Holbein, Van Dyck, Jewish artists Jacob Epstein and Isaac Rosenberg and Steve McQueen, the black-British Turner prize winner. A number came over after they were famous, others found their talents awakening in Britain.

The brilliant architect Zaha Hadid moved from Iraq with her family in 1972. She studied here and reached the very top. Jung Chang, the Chinese author of the best-seller Wild Swans, developed her voice here; the Jewish-Iraqi Saatchi brothers didn't arrived pre-cooked for success. They were made in Britain. So back to the inventive Mr Green. Has he given any thought to the immorality of what he calls his "selectivity" policy? Cherry-picking talent from developing nations is theft. To say that those who have shall have plenty more but those who don't can just bugger off is hardly Christian, or just or even sensible.

My English mother-in-law is in her nineties, and now, like many old folk, more needy than she once was. She is in a nursing home where most of the workers are "foreign". An acquaintance with a severely disabled child depends totally on migrant carers, day and night. These dedicated migrants would not win an audition for The Nutcracker or start hedge funds.

The British Isles are highly populated and need rational and fair immigration policies fit for purpose in a globalised world. This latest wheeze is neither. The super-successful can and will move to wherever there are better offers. They have no attachment to any nation. They will contribute less than Green believes and for obvious reasons. Then he bars those with potential and keeps out willing, hard workers.

Bountiful and fecund has been the encounter between British society and dreamy, aspirational incomers full of promise. Without them the nation will get torpid and lose dynamism. But by Jove the Tories will be popular, and that's what matters these days.

y.alibhai-brown@independent.co.uk