At the time of the Census, the majority of Polish-born people in Britain were those who had stayed or returned after serving with British forces during World War II. Areas like Swindon or Nottingham were part of this historic settlement.

Since the Census, the majority of arrivals are workers taking advantage of the EU's free market rules: London, for instance, has seen a massive rise in the number of eastern-European catering and construction workers filling apparent gaps in the labour force.

For more on this, see the link at the bottom on "what's changed" which explains immigration from eastern Europe.