There is a most mysterious drift which causes people to relocate from Labour constituencies to Tory ones. And since constituencies are all supposed to have the same number of electors in them (75,000) this means that from time to time the boundaries have to be redrawn by the completely apolitical Boundary Commission.
But for decades governments have been delaying the inevitable. Tony Blair didn't want to do it; nor did Gordon Brown, The Lib Dems blocked the 2010-2015 coalition government from doing it. Post-2015 David Cameron was on track to do it and Theresa May has continued that policy.
But with a 20 year backlog the redrawing required to equalize the districts is now quite extreme. The smallest area is Wirral West (Lab) with 54,000 voters and largest, at nearly double that, is the Isle of Wight (Con) with 105,000 voters.
That means the people of the Wirral have double the representation of the Islanders, which is hardly democratic.
Most amusingly, the proposed changes abolish Jeremy Corbyn's constituency of Islington North (68,000 voters.) In a typically brain dead socialist fashion JC intends to argue his constituency deserves to survive because the poor people who live there have "more complex needs." Why more complex needs justify over-representation he does not say.
If he fails to save Islington North one expects he'll find it quite easy to get another berth though. He has a lot of support on the ground.