Everybody's looking out for the little man but nobody cares about the big fella. Not even The Great Provider, St Michael. Call me blasphemer (and may I drown in a rain of speciality coleslaw if I lie), but the store that is all things to all men ostracises me.

Yet Marks & Spencer caters for every conceivable other minority. Here are loud dressing gowns for retired criminals and brown wool ties suitable only for Dundee librarians. Here, women of substance buy insubstantial lingerie. Here are gay socks for rent boys and muffin-and-beige, single- check shirts in easy-iron cotton twill for people who sit at plastic garden furniture writing why-oh-why letters to newspapers. Wait long enough and you will spot Margaret Thatcher on her way to the Political Underwear Department.

And at the end of the shopping day, unsold walnut salads are rounded up and distributed to the walnutless. So much for the little man. What about the big man? What about Terry Waite? And Jeremy Clarkson? What about me? Big men are no small minority. Yet can we buy a pair of size 12 shoes? No we can't. Big men despairing for lack of shoes, sometimes throw themselves off bridges where they have to stand with their heads sticking foolishly out of the water.

Last week, there was a rumour, or perhaps it was a dream, or a malicious trick by small people. Anyway, word came down that Marks & Spencer's Baker Street store was stocking size 12 shoes. And not a moment too soon. My current shoes were dead. They smelt of wet pony. People looked at me on the bus as though expecting to see a wet pony sitting there.

M&S has 20,000 men's shoes, laid out in the order of maximum difficulty. The small sizes are on the top shelf, where the small men can't see them, and the large sizes are on the bottom, so the big people have to crawl like men who have come to fix the carpet. The shoe sizes are displayed secretively inside the heel of each shoe, where they are hidden by the shelf above. You must serve yourself.

After a fruitless half-hour on my knees pulling shoes in and out, I cornered a member of staff. "The 12's," I said, "I can't find them." She must have heard the rumour, too, because she said: "Have you looked under?" I said I had. "No, under," she said.

I divined a sort of logic here: if the biggest shoes were on the lowest rack, then even bigger shoes might somehow be more under. Sure enough, I had only to lie on my stomach on the floor and stretch my arm out underneath the display to feel the tantalising toes of other, distant shoes, in a kind of inner sanctum, a shoe space whose existence is only rumoured, even among sales assistants. Sweating, I managed to hook out several of the mythical shoes. They were size 11.

Now the assistant was standing over me. "I'm afraid we don't do size 12 after all," she said, crushing my hope with a smile. I rolled over and stared up at her. I could see why small people feel an exaggerated need to assert themselves. "What has Margaret Thatcher's bottom got that my feet haven't?" She couldn't answer that.