The agency is understood to be in contractual negotiations regarding the account, after triumphing in a pitch.
London Elects kicked off a review of its marketing activity in April, with the process overseen by the Greater London Authority.
WCRS&Co is expected to be responsible for launching print, radio and digital campaigns ahead of the Mayoral and Assembly elections, which are due to take place on 3 May 2012.
The campaigns, which will roll out in early 2012, will focus on issues such as drawing attention to when the election takes place, how people can take part in the election process and where members of the public can find their nearest polling station.
Each of the campaigns will also focus on directing people to the London Elects 2012 website, which is currently being developed ahead of the elections.
Farm Communications handled the equivalent marketing activity for the election held in 2008, in which the current London Mayor, Boris Johnson, triumphed.
The London Elects campaign will be WCRS&Co's first win under its new chief executive, Matt Edwards.