Government has made no such assessment. The Electoral Commission conducts accuracy and completeness assessments of the electoral registers. The Electoral Commission’s most recent research was on the December 2015 electoral registers and can be found on its website.
The boundary review is currently being carried out by the four Boundary Commissions, which are statutorily independent bodies, using the December 2015 electoral registers, as set out in primary legislation passed by Parliament.
Registers used for a boundary review are necessarily a snapshot and the registers have always continued to change while a review takes place.