14.If there are three or more candidates, the Mayor will be elected under the supplementary vote system which gives voters the opportunity to express a first and second preference in respect of the candidates for election. (If there are fewer than three candidates, the 'first past the post' voting system will be applied.)
15.Assembly members will be elected by the additional member system. There will be twenty-five Assembly members; fourteen will be elected for constituencies and eleven will be elected on a London-wide basis. The fourteen constituencies will be established by order under the Act.  The Local Government Commission made recommendations on Assembly constituencies under Part II of the Greater London Authority (Referendum) Act 1998. The recommendations were published on 30 November 1998, following a London-wide consultation exercise. Ministers have announced their intention to accept these recommendations.
Background The Greater London Authority Elections to the GLA