But Mr Fox said there was "no chance" of a challenge to Mr Cameron's leadership before the next election - scheduled for 2015 - as such a move would be "absolute madness".
Israel insists on seven days of absolute Palestinian quiet before any move can be made towards implementing the political ingredients of the Mitchell commission's proposals, and thus haul the conflict back towards negotiations.
Many public figures have failed pretty dramatically, but through employing the seven key abilities of absolute perseverance, these people were able to move beyond failure.