Given the current polling and lack of time and opportunities for the polling to change, it is likely Cameron and the Tories in a little under three months time will be out of Downing Street, which in all likelihood means there will be a vacancy at the top of the Tory party.
The current favourite is Boris Johnson, in past Tory leadership elections it has been profitable to lay the favourite. Another reason for laying Boris will be if the Cameron project is seen to have failed, it is unlikely the Tory party will elect another Old Etonian, Bullingdon member.
For largely the same reasons it might be prudent to lay George Osborne, as he will be seen as the continuity Cameron candidate, more crucially, he will forever be associated as the architect of the omnishambles budget of 2012, from which the Tory poll ratings have never really recovered from.
So who to back? The value may have gone out of Theresa May, but you can still back Philip Hammond at 14/1.
If the Tories do lose power in May, a lot of Conservatives will see reuniting the right as the way to power in 2020. Who better than Philip Hammond, who has said in the past he would vote to leave the EU and has also said gay marriage caused a real sense of anger to attract back the UKIP defectors?
If you fancy an outsider, and the Tory Party does have a history of picking as leader someone who was long odds only a few months before they became leader, Jeremy Hunt and Sajid Javid may be the way to go and they can be backed at 33/1 and 16/1 respectively.
The odds on the next Tory leader are available here.