Simon Carr: Bercow undermined by the embarrassments of Mrs Speaker

Sketch: I'd say a challenge is now a certainty and a new Speaker the highest probability

A question to the Work and Pensions minister produced some insider chuckling. A Tory backbencher had asked: "Does she recall the parable of the 10 wise virgins and the 10 foolish virgins?" Oh yes, very good. It drew a good humoured smile from the Speaker, slightly rueful, perhaps.

The revelations from Mrs Speaker over the last few days have created a minefield of double entendres round the Speakers' office, and you could see John Bercow wondering if a foolish virgin was better than a wise virgin but that neither was really apropos just now.

Now Mrs Speaker is a dignified part of the constitution, she will find herself embarrassed. In her younger days, she told the press, she'd get so sloshed she'd fall asleep on the tube and find herself in Upminster. That's a long way to be unconscious. She'd also pick up strangers in bars and have sex with them. Black-out drinking and indiscriminate sex? I'm an exhausted liberal and have to husband my indignation. Truth to tell I can't get worked up about it.

But acts have consequences, as life goes on. Mrs Speaker meets a lot of people. She meets journalists. She may meet me, say at a reception. I will know for certain that I've never had sex with her. But she won't be able to say the same about me.

Now, that's not an insuperable problem for the wife of Britain's first commoner. Goodness knows there are dignified parts of the constitution who make Mrs Speaker look like Mother Teresa. The Duchess of This and the Countess of That. But the difference is that their various Highnesses, Graces and Ladyships haven't given a double page interview to tell the world their shagging habits.

So, if there's trouble for the Speaker, it's not what his wife did then, it's what she's doing now. Slagging off her husband's party, attacking the leader of the opposition, and to keep her political ambitions alive she has to give an insane interview to reveal things any normal person would draw a veil – or burka – or great racing sail – over.

The Speaker is supposed to be above politics, so it does matter a bit. Things haven't developed entirely to his advantage over the last three months. He isn't thought to preside impartially in the House. His deputy speaker plan (to make parties vote only for the candidate from their own party) has been rejected by the Procedure Committee. And the loathing he inspires among the Tories may well see his majority cut in Buckingham and a defeat in the House if he is returned. Mrs Speaker has released the indignation of those who have more than they need for purely personal purposes.

I'd say a challenge is now a certainty and a new Speaker the highest probability.

simoncarr@sketch.sc