The Sketch: Mask of severity cracks at legislative game show

"OPEN-MINDED though I am, masochism has never had any attractions for me," confessed Glenda Jackson, responding to an impertinent inquiry about her private appetites from Dr Stephen Ladyman.

He had invited her, should she be at all that way inclined, to indulge in the delicious degradation of a rail trip to Ramsgate, a journey that she would have to make in "an antediluvian carriage knee-deep in filth". When I see Ms Jackson in the house I'm afraid I can't help but think of Oliver Reed, wrapped around her like a freakishly hairy boa constrictor, but Mr Ladyman's choice of phrase provoked quite another flashback. Surely these were the very words used by Mary Whitehouse to describe the notorious "Tchaikovsky's wedding night" scene in Ken Russell's overheated biopic about the composer - a scene in which Tchaikovsky failed the nuptial assay of his manhood, looking on aghast as Ms Jackson writhed unsated on the floor of a Tsarist sleeper carriage, like a Connex South East commuter who has finally gone mad.

Dear me, how different she is today. Any masochists in the house - and one assumes there must be a couple - will have recognised with a secret thrill that her talents lie in quite the opposite direction. On her showing in the Commons she would make a formidable maitresse, the features sculpted into a mask of implacable severity, the stern voice with that nasal topnote, which operates like auditory cat-o'-nine-tails, flicking at whichever cringing MP has risked a question.

She does smile now and then, it's true, usually when a frontbench colleague has stung the Opposition, but what a chilly and transitory thing that smile is - more a flickering contemplation of cruelties to come than an expression of warmth. When she assures the House that "every penny" of road charges "will be spent on improving road services in London" you can't imagine that anyone would dare to spend a penny in any other way.

That this impression might be misleading was revealed by closer inspection in one of Westminster's salles privees. Because later in the afternoon Ms Jackson was addressing Standing Committee A, considering the Greater London Authority Bill, the legislation which paves the way for a London mayor.

Of course the transformation isn't magical - for long periods she wears the sort of expression you might summon if asked to mime "Witchfinder- General listening to a plea in mitigation" - but the vigour of the procedures does seem to exert a broadly mollifying influence.

Standing Committee A would lighten anyone's mood, being conducted by its chairman, Nicholas Winterton, as if it is an odd kind of legislative game show. Mr Winterton speaks as though the committee members are in the Upper Circle of the Royal Albert Hall, rather than just a few feet away, and manages the business with a choleric joviality, booming his catchphrase - "As many as are of that opinion say AYE!" - in the unmistakable cadences of Bruce Forsyth.

His brisk bark can be unsettling: "Mr Chairman, you're so frightening I've completely forgotten what I was going to say," confessed John Taylor, after he'd risen to intervene during a discussion about ensuring that the Mayor's staff represented the diversity of London's citizens.

After a few seconds to recover his wits he made his point - bald people should not be discriminated against either. Well, maybe wits isn't the right word, but Mr Taylor's little joke melted Ms Jackson further - after serving up her usual portion of procedural small print in reply she added that he shouldn't have said bald - the correct term was "follicularly challenged".

I could have sworn from the smile on her face that she was actually enjoying herself.