Boris Johnson strengthened his status as 9/4 favourite to succeed David Cameron as Tory Party Leader by becoming part of his Political Cabinet, according to bookmakers William Hill.
Meanwhile, William Hill make Tessa Jowell 5/2 favourite to succeed Boris as Mayor of London.
Hill's spokesman Graham Sharpe told BetOnPolitics.co.uk: "Political punters have earmarked Boris as the next Tory leader for some while, and his move into the Political Cabinet does his prospects no harm at all.
"The race to succeed Boris as Mayor of London is beginning to spark into life, with Tessa Jowell, the 5/2 favourite, and her nearest challenger, 4/1 chance Sadiq Khan, making the early running."
Elsewhere, William Hill on Tuesday also elevated Chuka Umunna to the position of clear favourite to succeed Ed Miliband as hefty support for the man who pre-Election was a 6/1 chance to be the next Labour leader, continued to push him ahead of former favourite Andy Burnham, now 5/2.
Latest Next Conservative Leader odds:
Prices correct at time of writing and courtesy of William Hill
9/4 Boris Johnson; 11/2 Theresa May; 8/1 George Osborne; 8/1 Philip Hammond; 12/1 Sajid Javid; 16/1 Michael Gove.
Next Labour Party leader: 13/8 Chuka Umunna; 5/2 Andy Burnham; 13/2 Liz Kendall; 9/1 Tristram Hunt; 20/1 David Miliband. Others on request.
Next Mayor of London: 5/2 Tessa Jowell; 4/1 Sadiq Khan; 7/1 David Lammy; 10/1 Zac Goldsmith; 20/1 Lord Coe; George Galloway; Doreen Lawrence; Michael Liebrich; Lord Sugar; 33/1 Eddie Izzard; 40/1 Jeremy Paxman; 50/1 Karren Brady; Russell Brand; Sol Campbell.