One has to work in Westminster not to know the seismic impact of immigration on Britain. A third of London’s population is now foreign-born; most babies born in the capital have immigrant mothers. On the city’s local radio yesterday, a phone-in was being conducted: why is it that, when you buy a cup of coffee or a sandwich, you are never served by a Brit, of whom 780,000 in London are on benefits? Why is youth unemployment so high, yet demand for immigrant labour so strong? Why do employers prefer foreigners?