Voting Systems:
Single-Member/Majoritarian Systems


For more information about First-Past-the-Post:

How the System Works:

The current system for electing MPs to the House of Commons is called First-Past-The-Post. There are 646 separate constituencies across the UK each electing one single Member of Parliament. In order to vote you simply put an 'X' next to the name of the candidate you support. The candidate who gets the most votes wins, regardless of whether he or she has more than 50% support. Once members have been individually elected, the party with the most seats in Parliament, regardless of whether or not it has a majority across the country, normally becomes the next government.

The system is used:
for elections to the House of Commons and local elections in Great Britain (but not in Northern Ireland) and in USA, Canada and India.

Arguments used in favour:

  • It is simple to understand.
  • The voter can express a view on which party should form the next government.
  • It tends to lead to a two-party system. The system tends to produce single party governments, which are strong enough to create legislation and tackle the country's problems, without relying on the support of any other party.
  • It provides a close link between the MP and their constituency.
  • The system represents the views of the people, as the candidate with the greatest support wins through a fair process.
  • The UK's democracy is one of the strongest in the world, it works and since no system is perfect, why should we go through the massive overhaul of changing?


  • Only one MP is elected in each constituency, so all the voters who did not vote for him or her are not represented. Their votes do not help elect anybody and so are wasted, they could have stayed at home and the result would not have been altered.
  • In 2005, in Great Britain, 19 million voters cast ineffective votes - that is 70% of those who voted. A high proportion of these voters are the same people every time, e.g. Conservative voters in County Durham or Labour voters in much of Surrey.
  • There is a lack of choice given to the voters. The candidates are selected by a small number of party members, and voters can only choose between parties. If the candidate selected for your party has views with which you disagree, you are left with no alternative choice within that party.
  • Voters are represented unequally. In 2005, the average number of votes per MP elected was: 26,906 for Labour, 44,373 for Conservative and 96,539 for Liberal Democrats
  • Concentrated support for a party produces results. In 2005, Conservative support was spread thinly over most of Scotland. They got 15.8% of the vote in Scotland, and only 1.7% of the seats. The Liberal Democrats got 22.6% of the Scottish vote and a similar share of the seats (18.6%) because they had strong support in a few constituencies and minimal support in most of the others.
  • The system leads to many people casting negative votes i.e. voting against the candidate they dislike most rather than for the candidate they like best.
  • The way the boundaries of constituencies are drawn can affect the results. Governments are often accused of gerrymandering, adjusting the boundaries of constituencies to influence the results.
  • In 2005, Labour won 35.2% of the total vote cast, but got 55.1% of the seats in Parliament, giving them power to form a government. Taking into account the low turnout (61%), only 1 in 5 of the registered electorate actually voted for the Government.

The Supplementary Vote (SV)

For more information about the Supplementary Vote:

How the System works:

With the supplementary vote, there are two columns on the ballot paper - one for the first choice and one for the second choice.  Voters are not required to make a second choice if they do not wish to.  Voters mark an 'X' in the first column for their first choice and a second 'X' in the second column for their other choice.

Voters' first preferences are counted and if one candidate gets 50% of the vote, then he or she is elected.  If no candidate reaches 50% of the vote, the two highest scoring candidates are retained and the rest of the candidates are eliminated.

The second preferences on the ballot papers of the eliminated candidates are examined and any that have been cast for the two remaining candidates are given to them.  Whoever has the most votes at the end of the process wins.

The system is used:
to elect the Mayor of London.


  • SV suffers from all the disadvantages of AV.
  • Unlike AV, SV does not ensure that the winning candidate has the support of at least 50% of the electorate.
  • SV does not eliminate the likelihood of tactical voting.

The Alternative Vote (AV)

For more detailed information about AV:

How the System Works:

The same constituency boundaries are used and voters would elect one person to represent them in parliament, just as we do now. However, rather than marking an 'X' against their preferred candidate, each voter would rank their candidates in an order of preference, putting '1' next to their favourite, a '2' by their second choice and so on. If a candidate receives a majority of first place votes, he or she would be elected just as under the present system. However if no single candidate gets more than 50% of the vote, the second choices for the candidate at the bottom are redistributed. The process is repeated until one candidate gets an absolute majority. The alternative vote is not actually a proportional system, but a majoritarian system. It looks most similar to the current electoral system.

The system is used:
in the Australian House of Representatives

Arguments used in favour:

  • The alternative vote retains the same constituencies and so the bond between members and their constituents is not lost.
  • Extreme parties would be unlikely to gain support by AV and coalition governments would be no more likely to arise than they are under First-Past-The-Post.
  • All MPs would have the support of a majority of their constituents.
  • It prevents MPs being elected on a minority of the vote. In 2005, only 34% of British MPs were elected by more then 50% of the votes in their constituencies. This is a decline from 2001, when half of MPs could claim 50% support of their constituents.
  • It removes the need for negative voting. Electors can vote for their first choice of candidate without the fear of wasting their vote.


  • Whilst it does ensure than the successful candidate is supported by a majority of his or her constituents, it does not give proportionality to parties or other bodies of opinion, in parliament. Research by Democratic Audit in 1997 showed that the results could actually be even more distorting than under First-Past-The-Post.
  • It also does very little to give a voice to those who have been traditionally under-represented in parliament.
  • There is no transfer of powers from party authority to the voters, and it does not produce a proportional parliament.

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