Looks at the activities of Mayor Ken Livingston and where he influences the planning process. The Mayor's powers include responsibility for leading London's Spatial Development Strategy (SDS) - the all-encompassing development plan for the capital due out in 2002. The SDS will administer housing as well as economic development, transport, town centres, central London and the environment in general. Gives details of eight strategies currently being prepared, which will feed into the SDS. Discusses additional strategies, including the proposal, unpopular with developers, that the SDS will ensure that 40-50% of all new homes will be affordable. Also looks at the likely effects of the Mayor's other key power, which allows him to refuse proposals for major planning applications. Suggests we are likely to see more schemes like St George's Imperial Wharf scheme, which includes 185 affordable homes and 850 private units. Diagram.