1. The populations forecast for the UK and Germany are entirely different. All population projections have a considerable degree of uncertainty, especially in current circumstances. However, until recent events, the German population that was expected to fall whereas that of the UK seems likely to continue to rise at the most rapid rate for nearly a century.
2. If, starting around 2011, the UK were to have no net migration our population would increase by about 4 million over the next 40 years and then flatten out, as shown by the green line in the graph below.
3. For Germany, this would mean a sharp fall of about 15 million in 40 years, continuing to fall thereafter.
4. The official projections for the UK are based on net migration of 165,000 a year as shown in the blue line.
5. In fact net migration has averaged 240,000 over the past ten years. This is illustrated by the red line which shows our population rising by about 20 million to 83 million in 40 years.
6. The Eurostat projection for Germany, based on net migration of 242,000 and a birth rate of 1.4 shows a population falling by roughly 5 million – the pink line.
7. The German statistics office has a projection based on net migration of 200,000 but a higher birth rate of 1.6 and a longer expectation of life. This is the line in dashes.
8. All these projections show the UK eventually overtaking Germany.
9. They are all, of course, being overtaken by recent events. UK net migration is currently 330,000.  Germany will now be even higher.