Western economies (including Britain's) do indeed "need" immigrants to do the jobs that the native population simply won't do. If you look particularly at the care industry, there are thousands of Filippinos and Africans working in nursing homes and hospitals. This is because the training they receive in their home countries is good, but because these countries are poor and unable to pay decent wages or offer good job prospects, they flock to the UK, where there is a severe shortage of carers and nurses for precisely the same reasons. the difference is, to a Fillipino or African worker, even the low wages and long, thankless hours in the UK are a massive improvement on what they can expect at home. The hotel and catering industry is the same, but tends to attract East Europeans; a waitress in London can earn probably 4 times more here than in Poland or the Czech Republic. Without these low paid "basic" workers, the economy, which is built from the ground upwards, would collapse in on itself, and then no-one would have a job. So yes, we "need" immigrants, but the reliance on them to do the jobs that British people turn their noses up at, is a dangerous thing.