Chris,

Further to my comment of Jul 3, I have put your estimates of the constituency vote in bands, along with classifying the constituencies by Region and by political party of the MP. For the Labour constituencies it is as follows.

https://manicbeancounter.files.wordpress.com/2016/07/reflabconstit.jpg

This is, of course, different from your split of probable / highly likely.

Looking at the constituencies where you estimate 60% plus the vote for an opinion, the Labour Party with 41% of the seats has

34 of the 54 seats with 60%+ Remain vote

89 of the 168 seats with 60%+ Leave vote

The Labour Party seems to represent a disproportionate number of constituencies which highly one-sided views. Most importantly, is that 23 or the 34 Labour seats with 60%+ Remain vote are in London. It is something concerning for a Party where maybe 40% of the membership live in London.