Labour and the Conservatives confirmed Ken Livingstone and Boris Johnson as their candidates last summer and the capital’s Greens named three-term London Assembly Member as their candidate in March.
The late selection of a candidate will place the Liberal Democrats at a disadvantage with no single voice to speak on London matters until the summer.
So far former MP Lembit Opik is the highest profile candidate to put their name forward although there is increasingly speculation that London Assembly Mike Tuffrey will enter the race.
The timetable for selecting a candidate is:
June 17 Close of applications
July 3 Interviews and shortlisting
July 11 Deadline for appeals
July 11 Deadline for candidates to submit manifestos
July 12 Publication of shortlist
July 18 Postal ballot mailed out to members in London
July 25-29 Hustings meeting
August 10 Deadline for returning ballot papers
August 12 Count and declaration of result