David Cameron has made waves this morning with his hint that he would block any attempt by Gordon Brown to become the new head of the International Monetary Fund. With classic English understatement, he told the Today programme  that Brown "might not be the most appropriate person to work out whether other countries around the world have debt and deficit problems".
He added: "Above all, what matters is that the person running the IMF [is] someone who understands the dangers of excessive debt, excessive deficit, and it really must be someone who gets that, rather than someone who says that they don't see a problem."
The reason this issue has arisen now is that Brown was openly networking at last week's economic conference  in Bretton Woods, birthplace of the IMF. He is now routinely described as the "favourite" to take over from Dominique Strauss-Kahn, whose considerable talents are badly needed by the French Socialist Party.
DSK, as he's known in France, is due to step down in November 2012 but may quit earlier to stand in next year's presidential election.
At this morning's press conference at Labour HQ, Ed Miliband was asked to respond to Cameron's comments. He said  the Prime Minister was "slightly jumping the gun" because there isn't a vacancy at the IMF, but added that Brown was "eminently qualified" for the job and would be a "strong candidate".
It would have been heretical for the Labour leader to say anything else, but he has handed Cameron another opportunity to play his favourite "son of Brown" riff.