But it appears that that challenge has come from Liam Fox whose letter to Cameron about cuts to the Armed Forces was leaked to and published by the Daily Telegraph yesterday. The public support for Fox from military commanders has angered Cameron, but he has issued a statement saying that he supports the Defence Secretary.
But for all that support Cameron and George Osborne told Fox to find even more cost-cutting measures and rejected Fox’s attempts to shield the Navy from the brunt of the cuts.
Mr Fox's letter warned of "grave consequences” if the defence budget were to be cut by 10%. But the next day the National Security Council met and ordered Fox to make even deeper cuts. It looks like Cameron has decided that the navy and naval equipment is not to be spared, which may be very bad news for shipbuilding on the Clyde.
However it seems that there is, as you would expect, massive support within the senior ranks of the military for what Fox is doing. This may be the first time for a very long time that the senior officers are behind the defence secretary, even if that puts them at loggerheads with the prime minister. Big name after big name, Dannatt, Jackson, Muxworthy, Williams have backed Fox, and of course Labour’s Ainsworth joined in to make a political point, as if he wasn’t a complete dead loss as Defence minister.
Given all the publicity, and indeed criticism of the last government for starving our soldiers of the funds to do the job in Afghanistan, it seems almost unbelievable that the prime minister will not go along with Fox’s demands.
And what a bonus we are throwing the Taliban. Now they know that the US has a timetable for withdrawal and they know that Britain is too broke to stay in the country, they must be rubbing their grubby hands with joy at the thought of getting rid of the enemy and then their corrupt, mentally unstable president, whom you will remember we helped them elect, and going back to exactly where they were in 2001!
Cameron is unmoved by all the pleading and Osborne is incandescent with rage telling ministers not to go over his head to the Prime Minister.
If not David Cameron will find himself in the same position as Gordon Brown, when troops turn their backs on him and refuse to speak to him or shake his hand.
If you and your chancellor, who have never served, insist on 10% cuts Mr Cameron, I think that the country will expect you to remove our troops from the war immediately. Nothing less will do.
Just as an afterthought. The MoD has to make savings of 10%. Cabinet ministers took a pay reduction of 5%. Is it me or is there an us and them situation going on here?
Pics: Liam Fox, Richard Dannatt