THE REFERENDUM CHOICE
At the moment MPs are elected by the first-past-the-post system, where the candidate getting the most votes in a constituency is elected.
On 5 May all registered UK voters will be able to vote Yes or No on whether to change the way MPs are elected to the Alternative Vote system.
Under the Alternative Vote system, voters rank candidates in their constituency in order of preference.
Anyone getting more than 50% of first-preference votes is elected.
If no-one gets 50% of votes, the candidate with the fewest votes is eliminated and their backers' second choices allocated to those remaining.
This process continues until one candidate has at least 50% of all votes in that round.
Who gets a postal vote in the AV referendum?
- People who have a permanent postal vote for a UK Parliamentary election - they will get a referendum postal vote too.
- People who have a permanent postal vote for a local election and are on the register for somewhere that is holding an election in May - they will get a referendum postal vote too (if they are are entitled to vote in the referendum)
- People who do not fall into either of the above categories but apply specifically for a postal vote for the referendum, or for both the referendum and other election(s) in their area.
Q&A: Alternative Vote referendum
A referendum will be held in May on whether to change the system for electing MPs. Here is a guide to the issue. What will the referendum be about?
It will ask the public whether they want to replace the existing first-past-the-post system for electing MPs to Westminster with a method known as the Alternative Vote.
What is the current voting system?
For Westminster elections, it's first-past-the-post. The candidate who gets the most votes in their constituency is elected as the MP.
And how is a government formed?
If one party gets an overall majority in Parliament - more MPs than all the other parties put together - they form the government. If no party gets an overall majority it is called a hung parliament. In this situation, as happened after the 2010 general election, two or more parties would be expected to work together to form a government. The system for forming a government would not change as a result of changes to the way MPs are elected.
Why do critics want the way MPs are elected changed?
They say too many votes are effectively wasted under the current system, with elections decided by a small number of voters in a handful of seats where no single party has a large majority. This discourages people from voting and makes them disengage with the political process. A key weakness of first-past-the-post, they say, is that two thirds of MPs are now elected with less than 50% of support of voters and this undermines democracy. They argue a different system will provide voters with more choice, force candidates to appeal to a broader section of the public and work harder to get elected.
How is Alternative Vote different?
The Alternative Vote - widely referred to as AV - system sees voters rank candidates in order of preference in single constituencies. People can nominate as many preferences as they like. Only first preference votes are counted initially. Anyone getting more than 50% of these is elected automatically. If that doesn't happen, the candidate with the fewest votes is eliminated and their second choices allocated to the remaining candidates in a second round of voting. If one candidate then has more than 50% of the votes in this round they are elected. If not, the remaining candidate with the fewest votes is eliminated and their second preferences (or third preferences if they were the second choice of someone who voted for the first candidate to be eliminated) reallocated. This continues until one candidate has 50% or more of the vote in that round of voting.
What do opponents of the change say?
Defenders of the current system say it generally leads to stable government and has historically reflected the will of the public in that unpopular governments have been voted out. They argue that first-past-the-post is straightforward and easy to understand. They say parties get elected on a manifesto and are expected to implement it, while under other systems more likely to produce indecisive outcomes, the government is decided after the election by horse-trading and "political fixes".
Why is a referendum being held?
A referendum on the Alternative Vote was not included in either the Conservative or Lib Dem election manifestos. However, the Conservatives - who largely oppose changes to the system - conceded a vote on AV as part of their offer to the Lib Dems in negotiations to form a government after the election. The Lib Dems have long urged changes to the voting system and although the AV system is not their preferred choice, they believe it is a first step towards a fairer system.
Is the Alternative Vote system proportional representation?
No. Parties could still form a government with less than 50% of first choice votes. Campaigners such as the Electoral Reform Society want a proportional system where the number of seats a party wins is more closely aligned with the number of votes they get. For many years, the Lib Dems have supported the more proportional Single Transferable Vote system.
What if I only want to vote for one candidate?
If someone votes for just one one candidate under AV, their vote will be counted once in each round that takes place. But any further preferences they could have stated will not be taken into account.
How do electoral systems work elsewhere?
Voting for the Scottish Parliament and Welsh Assembly is done through what is known as an additional member system. Some representatives are elected via the traditional first-past-the-post method but voters get to cast a second vote for "top-up" seats, allocated in proportion to the number of votes. In Northern Ireland local and Assembly elections, voting is done on a single transferable vote basis which sees more than one candidate elected from a single constituency. Voters number candidates in order of preference and all those passing a defined threshold are elected. Their surplus votes are distributed to other candidates on the basis of other preferences with low-scoring candidates progressively eliminated.
When will the referendum take place?
It will take place on 5 May 2011, the same day as elections to the Scottish Parliament, the Welsh Assembly, the Northern Ireland Assembly and local elections in many parts of England. Holding it then will save money as voters are already going to the polls across much of the UK, the government says.
What question will voters actually be asked?
At present, the UK uses the 'first past the post' system to elect MPs to the House of Commons. Should the 'alternative vote' system be used instead'? Yes or no?
When will the outcome be known?
The election is overseen by the Electoral Commission. Votes will begin to be counted at 1600 GMT on 6 May, the day after the poll. The outcome of the referendum is expected to be known later that evening.