What do we make of this afternoon’s reports?

On a day of apparently fast moving developments over the Labour leadership the main story on the Times website is of plans by Harriet Harman and David Miliband to challenge for the leadership.

Earlier the Evening Standard was reporting that “up to 10 junior ministers are willing to resign to force Gordon Brown to stand down, Labour MPs claimed today.”

The problem with both reports is their lack of identifiable sources. The Standard is based on quotes from a “former minister” while the Times pins their story on a “senior government source”.

This is getting to a stage, though, where the media speculation could force something to happen – either a display of unity from large parts of the party or else a real move to force Gordon out. Who knows?

Clearly this will affect the betting across a range of markets. Sadly most of them are with Betfair where there is an appalling lack of liquidity. Thus, as I write, you can get 2.05-1 on Harriet to be next PM but only £2 is available. If a Harman and Miliband challenge is for real then the price will move on both of them.

Mike Smithson