The great British worker faces a stealthy and growing threat. But this intruder is not Romanian or Bulgarian. He is not a benefit scrounger, swan-eater, immigrant or refugee. He is a robot, an indentured computer-labourer, and his arrival in vast numbers will transform the British way of work, and thus British society, more radically than anything since the Industrial Revolution.

A new study predicts that a third of British jobs could be taken over by computers and robots in the next 20 years. About 10 million of today’s positions are likely to be made redundant, according to the report from Deloitte and the University of Oxford.

Stephen Hawking this week warned that the artificial intelligence of machines could threaten the future of mankind by progressing faster than biological evolution. The real challenge is more immediate: robots will not out-think us or turn on us like Hal in 2001: A Space Odyssey; instead, they will replace some of us, by doing many jobs better and cheaper than we can.

The study shows that repetitive processing, retail work and clerical and secretarial jobs are most at risk. Employees paid £30,000 ($56,000) a year or less are five times more likely to be replaced than those earning £100,000 or more. This raises the prospect of a widening gulf between relatively unskilled workers and those with skills that machines cannot replicate — at least, not yet.

This process is already under way. Since 2001, jobs such as clerks, sales assistants, library workers, secretaries and travel agents have fallen by 40 per cent. Increasingly, machines will ­perform tasks it was assumed only humans could do: driving cars, ­diagnosing illness, processing ­insurance claims. Robots are replacing postmen, care workers and security guards. China is now the world’s largest buyer of robots.

Jobs requiring judgment, common sense, creativity, adaptability or detection are, for now, fairly safe. The sports trainer, actor, priest, social worker, fireman and MP are unlikely to be replaced any time soon. Robotic journalists may come sooner: last March the Los Angeles Times published the first automatic breaking news story, using an algorithm that writes up a short article after an earthquake .

Few economists dispute that this revolution is under way but they disagree on its implications. Some predict mass unemployment and social dislocation, a strange new world in which ­machines run themselves. But others point to history as proof that the advance of technology is ­always a long-term economic blessing, that economies are adapting and robots will ­create more jobs than they destroy.

In 1779 Ned Ludd smashed two stocking frames and became the enduring poster boy for protest against labour-reducing machinery. But the Luddites were wrong: the Industrial Revolution vastly increased productivity, created many more jobs and increased real wages across all classes. The same may be true of the robotic revolution if it prioritises new jobs that value ingenuity and ­imagination over rote work. If robots increase productivity, the reduced costs and increased profits will feed back into the wider economy.

Inevitably, the march of the ­robots will put an ever greater ­emphasis on education: the need for a skilled, adaptable workforce, able to perform the digital, managerial and creative tasks that ­robots and computers can not. Whatever the jobs of the future may be, they are certain to require higher skills, better training and deeper thought.

Philosopher Michael ­Polanyi argued that computers will never be fully programmable to perform all human tasks ­because humans do not know how they achieve their higher cognitive skills: “We can know more than we can tell.” There will never be an ­algorithm for judgment and common sense.

As machines increase ­productivity and profit, achieving higher output with fewer people, we may all have to work less and think more. With greater material comfort and more spare time, ­humanity can focus on creativity, imagination and thought. The Age of Enlightenment helped to forge the Industrial Revolution; the new industrial revolution could produce a new age of enlightenment.

Professor Hawking thinks the march of technology could ­destroy us, but it might just be the making of us. In 1930 Keynes ­suggested changing work ­patterns might usher in a utopia in which man’s greatest challenge would be “how to use his freedom from pressing economic cares, how to occupy his leisure, which science and compound interest will have won for him, to live wisely and agreeably and well”.

The ultimate effect of technology, it has been said, will be a ­factory run by one man and a dog: the man to feed the dog, and the dog to bite the man if he touches the machinery. That sounds fine to me: while patting his dog and watching the machine whirr, he could read a book.

THE TIMES