Just over 200 constituencies in England were either won by the Tories or had margins below 10k? Are you sure about that?

If that were the case then the Tories would be in opposition. By a very long margin. You're operating under false assumptions. The Tories alone won 296 out of 533 and that's without counting any won by the opposition with margins below 10k.
Quote Originally Posted by Aimless View Post
I was referring to the set of 100 constituencies with margins under 10k and 5k, respectively, which you might have been able to infer from the first part of the sentence of which you emphasized the second part. Only ~10 London constituencies had majorities under 10k, so that doesn't really help your case all that much.
So 10% in London alone. Plus Liverpool, Manchester, Bristol, Newcastle, Sunderland and every other city in the country?