To be honest: London is the only attractive city in England. It has some great flair. The rest is - meh. And EU membership was very important for Europe with all those companies making London their head of the EU branches. If you exclude London - what is left?
Rank Region national output pp
1 London £ 27.445
2 South East England £ 18.564
3 Schottland £ 16.284
4 East of England £ 15.976
5 South West England £ 15.789
6 West Midlands £ 15.152
7 East Midlands £ 14.994
8 North West England £ 14.953
9 Yorkshire and the Humber £ 14.953
10 Nordirland £ 13.430
11 North East England £ 13.184
12 Wales £ 13.084
Actually. Without London the UK is one of the poorer countries in Europe. And their strength is based on very close ties to EU.
Just a very intersting graphics showing how welfare is distributed among europe:
http://ec.europa.eu/eurostat/statist...0%29_RYB15.png
England doesn't look that good. Actually it is more probable that after Brexit, London will be closer to the rest of the country and not the other way around.