The local Borough Elections for Richmond Upon Thames full Council will take place on Thursday 6th of May (7am-10pm). The deadline for postal vote applications is 20th April.
Not to be confused with the General Election (still to be announced) this could occur on any date up to the deadline of June 3rd and may actually end up being combined with the local elections.
See Richmond Council site for further info. www.richmond.gov.uk/elections.