By way of London Says, the business case for immigration made (pdf) by London First:
In recent years, a flexible labour market has enabled us to recruit workers internationally to make up for the shortfall in London's workforce caused by skills shortages and a declining working age population. Migrant workers fill roles essential to maintain London's world city status.
It worries about the new restrictions on non-EU migrants, wants the points system better explained, the London workforce upskilled and better data to help the boroughs cope. The stats are interesting: 40% of immigrants come to London which has grown by 800,000 people since 1998; nearly 400,000 jobs have been created in this time of which nearly 90 percent have been filled by people born outside the UK; nearly a third of London's population were born overseas and by 2026 there could be over a million more people living here. A world in one city indeed.