Overview of the Act
The principal legislation governing parliamentary constituencies and boundary reviews is the Parliamentary Constituencies Act 1986 ("the 1986 Act"). The Parliamentary Constituencies Act 2020 amends the 1986 Act and makes provision in respect of:
the number of parliamentary constituencies;
the rules governing the setting of the boundaries of parliamentary constituencies;
the conduct of boundary reviews by the Boundary Commissions; and
the process for bringing the Boundary Commissions’ recommendations into effect.
	The existing parliamentary constituencies in England are based on data from 2000; those in Scotland, Wales and Northern Ireland are based on data from 2001-2003. In effect, the current constituencies reflect how the UK population was at the beginning of the century and do not reflect changes in demographics, house building and migration.
	Also, as a consequence of earlier legislation, there is currently a significant difference between the sizes of the electorate in many parliamentary constituencies.
	The combined effect of this amending legislation and the retained elements of the 1986 Act will allow the Government to meet one of its 2019 Manifesto commitments - to "ensure we have updated and equal Parliamentary boundaries" and to do so on the basis of 650 constituencies.
	The measures in the Act follow and build upon the written statement of 24 March 2020, ‘Update: Strengthening Democracy’ (HCWS183 and HLWS179 ), in which the Government set out its policy position in relation to the boundaries of parliamentary constituencies.
	In developing the provisions, the Government has taken into account representations from colleagues on all sides of the House of Commons, and from the Public Administration and Constitutional Affairs Committee. The Government has also engaged with representatives of the parliamentary parties on the changes concerning the boundary review process.