Aero Mad,
Afaik, UK population is still going up, and to some extent for the better. There is an HSBC report out there somewhere pointing out that because of previous immigration, and our now increased birth rate, the UK economy is going to look a lot better in 2050 than, for example, France or Italy.
Milton Keynes, Northants, eastern Warwickshire for starters all have extensive housing developments planned.
Immigration is always a touchy subject, but Silver may not be too far off with the Birmingham figure - are we talking city or metro though, quite a big difference, easily puffed up.