There are usually so many voters in any given UK constituency that a tie between candidates is a very unusual thing indeed.

While there were a couple of very close results in the 1997 UK General Election – with Mark Oaten gaining the Winchester seat with a majority of only two votes (in a result that was later annulled) and Adrian Sanders gaining Torbay with a majority of 12 – we have to go back to 1886 to find the last time there was tie in a constituency. That year, the Ashton-under-Lyne seat saw a dead heat and according to the rules of the day, the returning officer had the casting vote.

[Read more: General Election 2017 – Britain decides]

However, what would happen if there was a tie in a constituency in the General Election of 2017?

If a result is close (or if a candidate falls just short of the amount of votes required to retain their deposit) a recount can be requested. This can be a broad recount of 50-vote bundles but in the case of a very close result, the returning officer can order a complete recount, where every ballot paper is counted again. There is no limit to the number of recounts – the UK ‘record’ is seven – but if the same result recurs the returning officer can refuse a recount request.

If there is a tie, then according to current election regulations, the acting returning officer decides the result by drawing lots. There is no fixed rule as to how lots are drawn, and it’s up to the returning officer in question to decide the method. Common examples would include a coin toss, drawing straws or picking names from a hat.

To find out more about what happens at an election count, click here to read our guide.