Boris Johnson, the 4/9 favourite to be the next Mayor of London, is following a canny strategy designed to mobilise the Conservative vote. His 'Zone 5 and 6' strategy (based on Travelcard zones) involves him travelling, often by train or tube, to outer areas like Hillingdon and Sidcup and meeting commuters at stations. He has also been paying some attention to the Royal Borough of Kensington and Chelsea which is solidly Conservative but had a poor turnout at the last mayoral election.
He is following the 'below the radar' tactics used by Michael Howard which although they only produced a 0.6 increase in the Tory vote at the last general election led to the Conservatives gaining 23 extra seats. However, Bozza will probably be not using the 'dog whistle' tactic. The problem with the dog whistle (a focus on issues such as migration) was that it could be heard by everyone and reinforced the suspicions of some AB voters that the Conservatives were the 'nasty' party.
Policy papers issued by the Johnson campaign make no reference to the Conservative campaign and come in a variety of colours (a colleague of mine in Australia has done some fascintaing work on colours and politics). Ken Livingstone has similarly avoided branding himself as the Labour candidate, recalling his earlier spell in office as an independent repudiated by the Labour machine.
In a sense this is all fair enough as Londoners are electing an individual to a powerful post as much as they are voting for a party.