Counting the votes
On 4th May 2012, the day after polling day, the counting of votes cast in the election of the Mayor of London and the London Assembly will begin.
This process will take place in three count centres across London: Alexandra Palace, Excel, and Olympia. Votes in these elections will be counted electronically.
The 14 Constituency London Assembly Members will be announced by the relevant Constituency Returning Officers. This will take place in the count centre.
The declaration of the 11 London-wide Assembly Members and the Mayor of London is made by the Greater London Returning Officer (GLRO). This will take place at City Hall once all of the votes have been counted.
How the Mayoral results are calculated
The Mayor of London is elected by supplementary vote. If a candidate receives more than half of all the first choice votes they are elected immediately. If this does not happen, the top two candidates with the most first choice votes go through to a second round. All other candidates are eliminated, but the second choice votes on their ballot papers are calculated. Second choice votes for either of the top two candidates are added to the totals for those two candidates from the first round.
The candidate with the highest combined total of first and second choice votes will be elected as Mayor of London.
How the Constituency London Assembly Member results are calculated
The 14 Constituency London Assembly Members are elected using the First Past the Post system. This means that the candidate in each constituency with the most votes is elected as a Constituency London Assembly Member.
How the London-wide Assembly Member results are calculated
The 11 London-wide Assembly Members are elected using a form of proportional representation. Votes from across London for the London-wide Assembly Members are added together. The 11 seats are then allocated based upon a mathematical formula – the Modified d’Hondt Formula. This takes into account the total votes cast in the London-wide ballot together with the number of Constituency London Assembly Member seats that each political party has already won.
11 rounds of calculations take place to fill the 11 vacant Assembly Member seats, and the party or independent candidate with the highest result at each round is allocated the seat. Seats won by parties are allocated to party candidates in the order they appear on the relevant party’s list of candidates.
This voting system is used to ensure the overall Assembly reflects how all of London voted.
How your votes will be counted: e-counting
Due to the scale and complexity of the elections in London – with three ballot papers and three different voting systems – counting of the votes is carried out electronically, known as e-counting. This process has a number of stages to ensure that all votes are counted.
Once all the votes in a contest have been counted, the e-counting software will calculate the results. These calculations will be checked by the Constituency Returning Officer and the Greater London Returning Officer before being declared.
For more information please download our detailed factsheets, found below, or watch our short video on e-counting.