Tory leadership: RED Davis, BLACK Clarke, BLUE Cameron, GREEN Fox

But will he suffer the favourite’s curse?

For all the media is focusing on Ken Clarke’s speech this morning the big change in our implied probability chart based on best betting prices has been towards the 38 year old Shadow Education Secretary, David Cameron, who is now back to second favourite.

The Shadow Home Secretary goes into his platform speech today with the knowledge that in terms of public declarations he is almost a certainty to be in the final run-off ballot of members.

Cameron might by moving forward but the question for him remains – how can he convince enough of his fellow MPs to give their support to someone who only entered the Commons 52 months ago.

How must the Davis camp wish that the MPs ballot was not in secret? The Shadow Home Secretary built up a huge power base in the parliamentary party heading the Maastricht whips office in John Major’s time – but then you could monitor precisely the way people voted. This time the ballot is in private and there must be a risk that some of those who have lined up in public for him might tick a different name on the ballot form.

There’s also the standing rule of Tory leadership contests that the front runner never wins. In 2001 Michael Portillo even came top of the first ballot of MPs but then did not make it to the final.

So still a long way to go for Davis but a good speech today should steady the nerves of his loyal followers and those punters who backed him down to 1/2 and now might be a bit concerned by the current 0.8/1 Betfair price.

Tory leadership betting prices

Conventional bookmakers best price: Davis 8/15: Clarke 10/3: Cameron 4/1: Fox 12/1: Rifkind 50/1

Betfair betting exchange: Davis 0.8/1: Clark 4.6/1: Cameron 3.8/1: Fox 11.5/1: Rifkind 155/1

BinaryBet spread market. Davis 55-63: Clarke 18-24: Cameron 10-16

Mike Smithson