Arbuthnott Commission

The Arbuthnott Commission on Boundary Differences and Voting Systems was set up in July 2004 by Alistair Darling, then Secretary of State for Scotland, under the chairmanship of Sir John Arbuthnott, to examine various consequences of having four different systems of voting in Scotland, and different boundaries for constituencies of the House of Commons (Parliament of the United Kingdom, at Westminster) and the Scottish Parliament (Holyrood).

In 2004, Scotland had three different voting systems: plurality (first past the post) for Westminster and local government elections, and two different systems of proportional representation (PR) for European Parliament and Scottish Parliament elections. The number of systems was due to rise to four in 2007, with the introduction of a third PR system for local government elections.

Also, until 2004, legislation required Scottish Parliament constituencies to have generally the same boundaries as Scottish Westminster constituencies. This link was broken by the Scottish Parliament (Constituencies) Act 2004, and a new set of Westminster constituencies was created in 2005. Scottish Parliament constituencies remain as they were when created in 1999.

The commission published its final report in January 2006, making various recommendations. Full implementation of the commission's recommendations would be beyond the competence of the Scottish Parliament, and would require Westminster legislation.

...
Wikipedia