Votes that determine elections Votes that determine elections
People often speculate about the number of votes that actually made the difference in any given election. In other words, the minimum number of net votes that needed to be cast for the opposition in sufficient seats to produce a different result. This number, in comparison to the total electorate, is quite small.
For each election, apart from February 1974, the Key Votes are calculated as the summation of half the majority, rounded up to the next whole integer, in the smallest number of the most marginal seats that would have made the difference. Comparisons between elections don't make much sense because of complications such as boundary changes. The calculation of the government majority excludes the Speaker.
|Year||Govt||Majority||No of Seats to|
reverse the result
|Key Votes||Electorate||% of|
§ votes in non-Labour marginal seats required to give Labour a majority
¶ This figure, unlike that for previous years, assumes that the Speaker and three Deputy Speakers (who do not normally vote) are excluded, along with the 5 Sinn Féin MPs (who did not take up their seats)
Political Science Resources
© Richard Kimber
Last Modified: 22 Oct 12