>I've been following Madeline Sumption on Twitter for a while. I think she has a political motivation and I don't consider the Migration Observatory to be a valid source. Sorry.

I don't know them, but I'll take your word for it. However, will point out that it is in no way worse than the source you provided (no source)

How about Migration Watch?

https://www.migrationwatchuk.org/statistics-population-count...

Compared to the total non-UK born population, Pakistan + Bangladesh are a tiny blip.

Another source:

http://www.telegraph.co.uk/news/general-election-2015/politi...

More from the ONS:

https://en.wikipedia.org/wiki/Foreign-born_population_of_the...