Fifty years ago, our Commission on Electoral Reform examined questions that have returned to the centre of political debate today. Published in 1976, its report followed the two general elections of 1974, a period of minority government, and growing debate about the effectiveness of Britain’s political system.

Chaired by the historian Lord Blake, the Commission weighed the arguments for and against the First-Past-the-Post (FPTP) electoral system and explored possible alternatives. It sought an electoral system that would:

• favour single party government, without allowing a party to secure a majority on considerably less than 50% of the votes cast;

• set a threshold to exclude very small parties, except those based on national identity;

• enable major parties to win representation in areas where they had sizeable support but fell short of a majority;

• preserve a close relationship between MPs and their constituencies;

• be simple to understand and require as few changes as possible to the existing system; and

• enhance the role of individual voters while retaining an important role for political parties.

The Commission’s central recommendation was an Additional Member System (AMS). Three-quarters of MPs would continue to be elected by First Past the Post in single-member constituencies. The remaining quarter would be additional members, allocated to parties on a regional basis to bring their shares of seats more closely into line with their share of votes. The aim was to combine greater proportionality with the familiar constituency system.

The Commission was concerned in particular with the fact that the decline in the two-party vote was not reflected in parliamentary representation. One passage from the report is particularly striking 50 years later:

“The fact is that in 1974 even with the present method of election which by its very nature tends to favour the two party system, far fewer people than at any time since the war supported the two major parties, presumably showing by their votes that they are not content with the choice between only those two. If this is so, there must clearly be something to be said for a system which allows the voter a third or a fourth choice with a reasonable chance that his vote will be of value.”

That decline in support for the two main parties has since gone much further. In both February and October 1974, Labour and the Conservatives together received about 75% of votes cast. At the 2024 general election, their combined share was about 57%.

This comparison does not settle the argument for or against electoral reform. But it underlines the continuing relevance of the questions the Commission posed: how should an electoral system respond to a more fragmented electorate and party system? And how should it balance representation, voter choice, simplicity, and effective government?

The Prime Minister Andy Burnham has announced that there will be a new National Commission on Electoral Reform. We hope our 1976 report can help inform the current debate about how Britain’s electoral politics have changed and whether a different electoral system would better serve voters and government in the future.