Does the review of the parliamentary constituencies still have to be approved by Parliament, and if so, will the results of this election prevent that from happening?
The Boundary Commissions are due to put forward proposals in September 2018. Before the new boundaries can be put into law, Parliament will have to approve them. If the changes are rejected, then the existing boundaries will continue in force.
Given that only the Conservative Party is reasonably happy with a 600 seat House of Commons, it must be quite possible but not certain that the results of the boundary review will be rejected.
This was the key fact that I was considering. Going from 651 to 600 means with certainty that 51 incumbents will be out of a job, without taking into account any changes in boundaries.
Britain would be better off going to continuous redistribution like in Australia. Seats could be formally apportioned to the regions in England, and possibly in Scotland, so that the change of one seat in 500 (0.2%) does not trigger an England-wide review. If the number of seats for a region changes, do a new review for that area.
If a constituency is more than 10% from the mean for a region, then adjust that constituency and other as necessary. If a significant share of constituencies in a region are more than 5% from the mean for a region, then do a region-wide redistribution.
Wasn't there an issue with how voter registration was being changed (from household to individual) before. Has that settled out?