There is, it seems, nothing spectacularly porous about the plumbing at Gillian Shephard's department. In a league table of leaky ministries published by a think tank last week, the former DFE notched up three embarrassing discharges of information between summer 1994 and March 1995. This is more than Defence or Environment, but a long way behind the Scottish Office, which was responsible for a gushingly indiscreet five.
On the other hand, last week's leak, which has effectively sabotaged John Major's recent attempt to reflate the Government's sagging opt-out drive at the start of the conference season, marked the third time in three years that Mrs Shephard has mislaid highly sensitive bits of paper.
All three leaks have been notable for their theatrical sense of timing, and the last two have left Mrs Shephard looking more honest and worldly-wise than her bosses.
Back in April 1993, when Mrs Shephard was Secretary of the then-separate Department of Employment, she wrote a letter to her predecessor at Education, John Patten, offering to help him in his battle over testing by suggesting that the looming boycott could be outlawed. "I have been considering an amendment in the law," she wrote, "to make it clear that industrial action is unlawful, as in the case of the threatened boycott of English tests, it is clearly designed to frustrate the carrying out of a specific statutory duty."
When the letter found its way into the National Union of Teachers' hands there was a predictable uproar, but the circumstances in which it was leaked have been the subject of a persistent rumour, confirmed by a TES mole this week.
"A photocopy of the letter was found one fine morning stuffed into teachers' pigeonholes in a secondary school in King's Lynn (in Mrs Shephard's constituency)," he says. "The photocopy was not addressed to anybody; I can't understand how it got there - did she want it leaked? Perhaps it fell out of her briefcase?" Anyway, the leaker was never rumbled.
Moving on to January 20 of this year, when a plain brown envelope arrived at the unsuspecting offices of The TES. Inside, another letter from Mrs Shephard, this time addressed to David Hunt, who then chaired the Cabinet committee dealing with education spending. It warned that job losses, bigger classes and "a renewed battle with teachers" would be inevitable unless the purse strings were relaxed.
The letter was written in November 1994, but leaked at a time calculated to fuel fears about underfunding as the unions prepared for the Easter conferences, while at the same time distancing Mrs Shephard from the Chancellor, Kenneth Clarke. Again, the sender was never identified.
The hunt is on for the source of last week's revelation that the Education Secretary believes her Government to be "politically exposed" on education, and that "standards must not be overshadowed by arguments about the mechanics through which education is delivered" - an oblique reference to Mr Major's dogged faith in opting out. The DFEE has confirmed that an internal investigation is under way to unearth the mole, and that "of course the police will be called in if it is proved to be appropriate".
Mrs Shephard is again steering an adroit middle course - denying that she actually used the arguments in the leaked document at the Chequers summit, denying a rift with Mr Major, but admitting that "in the debate about education funding this year, the effects have been very patchy".