A good rule of thumb when feeding negative stories to the press about a Prime Minister, whose administration you work in, is not to do it from the office phone. A mighty row has blown up in Downing Street after a leak hunt has found the Deputy Prime Minister’s spokesman up to his neck in it after giving the Mirror a story about the Cameron and Osborne children playing in the Rose Garden. The Mail on Sunday reported the row yesterday without naming James McGrory as the leaker…

Cameron hit the roof and his staff got in Scotland Yard to trace the leak. McGrory’s study looks out over the Rose Garden and his phone made three calls to the Mirror just before they put a call in to Downing Street for a comment. On the day that Clegg announces that he is going to spend half a million on seven new LibDem SpAds across Whitehall, he should probably start thinking about an eighth…