I was going with friends to the south of France, but first I had to travel from London to Dover where we were due to meet. So I reported to a small hotel in Bayswater from which the coach would collect me and other holidaymakers.

It was midday. I had already read the papers and my holiday paperbacks were deep in my holdall. The only remaining diversion was the bar. Forgetful of my notoriously weak bladder, I downed two or three pints.

When the coach finally arrived I found a seat to myself and settled to enjoy the ride. But after about 20 minutes I began to experience an ominous fullness. If I can just hold on, I told myself and gritted my teeth, but soon my situation deteriorated from unease to severe discomfort. Eventually, glowing with embarrassment, I shuffled up to ask the driver if we could stop. "Tie a knot in it, mate, I'm late as it is," he said.

Seated again, a sort of numbness set in. Perhaps there was a chance I'd make it after all. Jaw clenched, I stared grimly at the green fields whipping past, willing us on towards the White Cliffs and the nearest loo.

My optimism was misplaced. The urge to urinate continued to grow until I was near bursting point. Ashen-faced, I once more plodded painfully up the aisle. This time the driver scowled in derision and shook his head before I even spoke. I shuffled back to my seat in black despair, knowing that now there was only one thing for it.

Inside my holdall was a thick hand towel which I folded double and tucked beneath me. Then, shielded by the holdall and gazing out of the window as nonchalantly as I could, I went. The relief was immediate. The flow seemed to go on forever and, numb as I was, it was difficult to know when I'd finished. The luckiest part was that I was wearing old tweed trousers whose thick, dark, material didn't show the stain. They and the towel quickly became drenched though not a drop leaked onto the floor. As far as I could tell none of my fellow travellers noticed anything, unless it was the relief on my face.

I spent the rest of the journey sitting in cold urine, worried that I might start steaming. There didn't appear to be any smell, although that surely was only a matter of time. As we neared Dover I slipped the sopping towel inside a plastic bag and push it back into my holdall.

I made sure I was the last to leave the coach by fiddling manically first with my holdall and then my shoe-laces, then carefully avoided eye contact with the driver as I squelched down the vehicle's steps. Then I fled into the gents to change into dry clothes.

Feeling human again, I found my friends and we boarded the ferry for France. They probably wondered why I preferred lemonade to a celebratory beer, and only a small glass at that.