UNDER the current first-past-the-post system, the candidate who gets the most votes in their constituency is elected as the MP, regardless of how large their share of the vote is.

The Alternative Vote (AV) would ask voters, rather than putting a cross next to one candidate, to rank all candidates in order of preference. They would enter a ‘1’ next to their first-choice candidate, ‘2’ next to their second choice and so on, and voters could select as many or as few candidates as they like.

If any candidate wins more than 50 per cent of first-preference votes, they would be elected. If no candidate reaches this mark, the one with the least first-preference votes is eliminated, and those voters’ second and third preferences are redistributed.

If necessary, the process is repeated until either one candidate has 50 per cent or more of the vote or there are no more preferences to be distributed.

People could vote for just one candidate under AV, as they do under the current system, and their vote for that candidate will count as long as they remain in the race.

You can vote in the local elections without taking part in the referendum tomorrow. But everybody who is registered to vote will have ballot papers for the elections and the referendum.