I can get another pager, but that’s not the point. I hate it when things aren’t where they should be, it’s an itch to scratch. To calm myself, I chant one of my spells. It has to be short, and repeated a specific number of times (three and seven are normally good; five works sometimes too, as does saying ‘times infinity’). Under my breath, I say, ‘If it’s gone forever, that’s OK.’ Then I mutter it twice more. Relief steals over me.

I’ve been using these rituals to cope since I was in my teens. I never trusted my parents to have locked the front door or turned off the gas. I would press the knob on the hob seven times, making an indentation in my finger, and then stare at it. I would do this at two in the morning, when everyone else was asleep. Mum and Dad never noticed. But my sister Clare would come down to find her anxious little brother and steer me back to bed. It was Clare, when we were both at university, who gave my rituals a name; she asked me how I was coping with my ‘obsessive compulsive disorder’. Clare usually knew more about me than I did.

In The Groucho’s vestibule, I have one more thing to do. I descend the narrow staircase to the men’s room. In the cubicle, I take a pinch of lumpy white powder from the cling film I’ve repackaged it in and begin a little ceremony with a Barclaycard on the top of the cistern. I am an unusual user; when strung out and unable to focus, this stuff calms me.

Two and a half snorts later, I’m myself. It is a wonder drug. Back upstairs, Petra tells me my guest has arrived; she shooed him to the bar. Tony Cannon, the Labour MP for Preston, is sitting by the window on the sofa I nabbed. He’s my age, mid-thirties, though I carry it better. His skin is rough, the colour and texture of cottage cheese, eyes deep in his greying sockets. His suit is a size too big. Unlike mine, it’s not a fashion statement. My grandmother would have told him he needs a good meal. Actually, what he needs to do is cut down the substance abuse. His red eyes dart like a cornered rabbit, obviously a line or two ahead of me.

‘What do you fancy to drink?’

‘Champagne?’

‘Flippin’ ’eck Tony. You have become the living embodiment of Todd’s Modern Labour.’ I catch the eye of the waitress.

If Todd is an abrupt rupture from Labour’s past, Tony Cannon is an evolutionary link. Perhaps the last authentic working man at the top of Modern Labour, complete with never-pressed C&A suit, he left school to become a train mechanic, then an organiser with the Transport and General Workers’ Union.