How Labour selects its new leader

The announcement of the next Labour leader at around 16.40 tomorrow will take some time, and the five candidates – who will have been informed of the result shortly before the public announcement – will have to sit in silence as they look up at screens displaying the result. Labour chooses its leader through an electoral college with three sections, each of which account for a third of the overall votes.

The sections are: MPs and MEPs, constituency Labour parties, and trade unions and other affiliated groups. The system means that the votes of the 271 MPs and MEPs carry vastly greater weight than the 170,000 party members. All voters rank the five candidates in order of preference.

The announcement, in Manchester, will take some time because the results are explained separately in each section. The candidate with the lowest vote will be eliminated and their voters redistributed until one candidate secures 50% of the vote in the electoral college. It may feel as if no candidate has won a clear mandate as the results are announced. This is because the votes in each section will be announced as a percentage of all elements of the electoral college. If the Sunday Times/YouGov poll is right and Ed Miliband secures 36% of first preferences of trade union members, this figure will appear far lower on the screen – as 12% of the overall electoral college. Capiche?

Gordon Brown, who has been in New York this week for the Millennium Development Goals summit, will make a brief return to the spotlight, speaking before the new leader is announced. Once the winner is declared he or she will then make their first speech as the new leader of the Labour party. The new leader's first challenge will come on Tuesday with the traditional leader's speech to conference.