Sebastian Coe has been a popular long-term bet for the election, as his odds creep down to 12/1 from 25/1 to push him ahead of Boris Johnson, who despite not ruling out a tilt at a third term is a 20/1 shot. With a number of independent candidates also rumoured to be in the running, the bookies offer 10/1 about the eventual winner not being a member of any of the major parties.
Alex Donohue of Ladbrokes said: "Jowell's position in the betting suggests she's a prime contender to be Labour's candidate for 2016. Upon confirmation of her intention to run, she has the honour of being the long-term favourite and if selected she'd be odds on to get the keys to City Hall."
Ladbrokes latest betting
2016 London mayoral election:
7/2 Tessa Jowell
5/1 Sadiq Khan
10/1 David Lammy
10/1 Alan Johnson
12/1 Sebastian Coe
16/1 Andrew Adonis
16/1 Diane Abbott
20/1 Boris Johnson
20/1 Doreen Lawrence
20/1 Michael Liebreich
20/1 Jon Cruddas
20/1 Margaret Hodge
33/1 bar
Winning party:
1/3 Labour
11/4 Conservatives
10/1 Any other
50/1 Liberal Democrats
16/1 Andrew Adonis
16/1 Diane Abbott
20/1 Boris Johnson
20/1 Doreen Lawrence
20/1 Michael Liebreich
20/1 Jon Cruddas
20/1 Margaret Hodge
33/1 bar
Winning party:
1/3 Labour
11/4 Conservatives
10/1 Any other
50/1 Liberal Democrats