IT's her greatest strength, but perhaps her greatest weakness. What makes the Conservative MP Louise Mensch so unusual is her apparent belief that the rules of politics somehow don't apply to her.
She always seemed fiercely ambitious, yet almost her first act as a new backbencher was to blow promotion by criticising her own side's half-baked proposals for rape law reform. When a tabloid dug up tales of decades-old drugtaking, she didn't claim apologetically never to have inhaled: she merrily confessed to all that she was accused of and probably more.
And yesterday, she sailed out of a critical Commons hearing into tabloid phone hacking early, blithely announcing to the TV cameras that she was off to get the kids from school. Cue outrage, even in some unpredictable quarters. But why?
It's not so much that she scarpered instead of waiting until the bitter end: over years of covering select committees, I saw many MPs trot out their questions, as she diligently did, and then leave (although rarely on such a high profile occasion). It's that she was so brazen about it. She could have slipped out muttering obliquely about a private matter: or hinted at some dire childcare emergency - a nanny off sick, husband away. That's what the rules for working mothers say: never let on how hard it is, and if you must, then stress it's a rare one-off.
But instead Mensch went out of her way to show she actively chose to go, tweeting afterwards that Thursday is one of her days to have her three children (she's divorced, and presumably shares access with her ex-husband) and so she usually works then from her Northamptonshire constituency, where the children are at school. It seems she simply decided that having said she would always be there on Thursdays, she would be there on Thursdays come what may: that the commitment to the children, at least on that day, trumped everything else (presumably on other days, the opposite applies).
Again, plenty of MPs of both sexes seem to be mysteriously unavailable at Westminster any time after Thursday lunchtime: doubtless some are on the school run too. But the unspoken rule is don't ask, don't tell. Keep the fact that that you really want to see your children, after being away for three nights, as your dirty little secret - because if you don't, we would have to face up to the emotional cost of the hours we expect you to keep. (Or indeed, to our anxiety over having made different choices ourselves).
It's the same in countless ordinary offices, where parents are quietly advised never to put anything down on paper about leaving early: just fabricate a client meeting every now and then and slip off early, like everyone else. It works. But it's deeply dishonest, perpetuating the myth that it's fine to work a 70 hour week or choose (as MPs do) between living several hundred miles from their children or dragging them up and down the motorway every weekend. And it's an excuse for nothing to change.
Because if it's not about Mensch blowing the gaff, then what? Let's not pretend another 45 minutes of her silent presence at the hearing would have broken James Murdoch: had she quietly fixed a playdate for the kids and stayed on, it would have been pure presenteeism. Let's not even pretend it's about her being a 'part time MP': it's long been acceptable for backbenchers (often men) to have a second job outside the Commons, which hardly seems any different. Certainly, don't pretend it's about being out of touch with ordinary working parents: where better than the school gates to see what life is like for them?
Some find Mensch herself annoying, of course: I do see that talk of facelifts and dressing nicely for your husband can grate, while others simply don't like Tories, or her apparent hunger for publicity. But you can't believe in parents' (and childrens') right to a family life, and in the benefits to both sides of flexibility, and in judging people by results not by time spent chained to a desk, unless you believe in it even for annoying people.
Mensch will get brickbats for this in the papers and vitriolic emails from constituents: so be it. But perhaps her children will remember that she was always there on a Thursday long after we've all forgotten. She's made the choice, and while it's not everybody's choice, that deserves respect.