Consider the UK population, farming & infrastructure only takes up 12% of the landmass. iThe equivalent pop of Wales,Northern Ireland and Scotland are concentrated in London and S/E of England. Westminster does nothing to change this. May I suggest this is why there is a tinderbox feel there.
Remember 1066, Norman the Conqueror invaded England via this area by boat. The sight of boats landing on English beaches from foreign lands is deeply rooted. Something Farage Riots caught onto very early on.
Westminster should have financial aid schemes to assist people crammed like sardines into London and S/E to spread around UK. Maybe @timharford.ft.com can do some projections on population growth if a policy like this was actually carried out.