Electoral reform: key issues for the 2010 Parliament

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All the major parties have proposed some form of electoral reform.  However, the nature of those proposed reforms and the implications for the House of Commons differ greatly.

Conservatives: fewer MPs

David Cameron said in 2009 that politicians had to “play our part and take a lead” in cutting public spending.  He proposed that the number of MPs should be cut from 650 to 585 and that constituency electorates should be equalised across the UK; they currently tend to be lower in Wales, Northern Ireland and in urban areas. To implement these changes, a boundary review under new rules would be conducted within five years. 

There were large disparities in constituency electorates at the 2010 general election.  The largest constituency was the Isle of Wight with 109,902 electors, more than five times the smallest, 21,780 in Na h-Eileanan an Iar.
Critics of the Conservative plans claim they are motivated by self-interest, suggesting that areas with low constituency electorates currently tend to coincide with low Conservative support.  These areas would tend to lose MPs under the plans.

Labour: AV

Labour has proposed a non-partisan Parliamentary Boundary Review to examine the rules for the redistribution of seats, together with a referendum on introducing the Alternative Vote (AV) system for elections to the Commons.  Provisions in the Constitutional Reform and Governance Bill to hold a referendum on introducing AV were withdrawn in the ‘wash-up' period before the election, to allow less contentious provisions to be enacted.
Under the AV system, voters rank candidates in order of preference.  The winning candidate must have 50% of the votes so the votes for lower-placed candidates are distributed in succession until one candidate has more than 50%.  The constituency link characteristic of the current first-past-the-post (FPTP) system is retained.  The AV system is not a proportional voting system, but a majoritarian one.  Critics point to the fact it can produce an even more disproportionate distribution of votes into seats than FPTP.

AV plus

The Independent Commission on the Voting System (Jenkins Commission), set up in 1997, recommended a mixed voting system, ‘AV plus'.  Some MPs would be elected using AV, with the rest being ‘topped up' from regional lists to bring more proportionality.

Liberal Democrats: STV

The Liberal Democrats favour the Single Transferable Vote (STV) system and 150 fewer MPs.  Under STV, voters rank candidates in multi-member constituencies.  The winning candidates must reach a certain quota of votes in order to be elected and the surplus votes for elected candidates and votes for the least popular candidates are redistributed according to voter preference.

Supporters of STV say there are fewer ‘wasted votes' under the system than FPTP and that it retains the opportunity for voters to evaluate individual candidates.  It also produces a more proportional result than AV - though not as proportional as party list systems.  Critics say the system is too complicated to understand and that the link between an individual MP and their constituency is lost.  Advocates of FPTP argue that proportional voting systems lead to weak and indecisive government.

Different electoral systems produce very different election results.  Electoral systems were prominent in the political negotiations in the days following the general election.  The consequences of the debate could define the course of UK politics for decades to come.