I remember some moments of the Gay News trial vividly, and I well remember my anxiety that I might, under cross-examination, give answers that would be unhelpful to the defence. The fact of the trial seemed far more shocking to me than the poem.

I couldn't believe that Denis Lemon, a young, brave and independent editor, was risking imprisonment for publishing it. I had long been a defender of what are now called gay rights, and was associated (along with JB Priestley, Angus Wilson, and other eminently respectable literary figures) with the Campaign for Homosexual Equality. I felt it my duty to bear witness on behalf of this poem and this poet and this magazine, even if I ended up looking a fool, as some friends assured me I would.

My father, a Quaker judge, stood by me throughout, as he had done with an earlier case over a book called The Mouth and Oral Sex by avant-garde novelist Paul Ableman, in which I also appeared, more successfully, as expert witness. The poem didn't shock me then, and doesn't shock me now. It isn't one of Kirkup's best, but it has good moments, and it didn't seem to me to be dangerously blasphemous. We weren't allowed to argue literary merit, but had we been, I would willingly have argued it. Iris Murdoch thought more highly of it than I did, but she wasn't able to speak up for it either.

I knew my role was to present myself as an image of responsible motherhood. I think, and hope, I was a responsible mother, so this wasn't a pretence. I seem to have told the judge that I had shown the poem to my 16-year-old son: this son, now an Oxford academic, confirms this, and says he now finds the poem "distasteful", but no worse. It certainly didn't ruin his life. I remember being much more shocked by the Rupert Bear Oz case and tried to hide the copy I had been sent but, of course, the boys found it. I also told the judge that my younger, 12-year-old son hadn't read Kirkup's poem because he didn't read much. This was a cheap crack at the expense of my son, Joe Swift, a young lad now famed as the Nick Hornby of the gardening world, but it got me out of a tight corner at the time.

What I didn't say was that during my lunch break at the Old Bailey I had nipped up to the Boy Scouts shop which was conveniently nearby to buy Joe some gear for a Cubs summer holiday - this would have been relevant, as much play was made in cross-examination about the risqué Gay News ads which featured double entendres about Boy Scouts and cubmasters dressing up in uniforms. Could I reveal to this easily shocked judge that my little lad was about to be entrusted by his mother to a chap dressed up as Akela? The older son survived the poem, and the younger the summer camp, so all ended well on that front.

I think the prosecution had no idea of Kirkup's status as a poet. He hadn't then published his startlingly frank volumes of autobiography, but several of his poems had appeared as poster poems, and one of his bird poems, adorned by a woodcut by Thomas Bewick, was even coincidentally affixed to my bedroom wall at the time of the trial. The judge and the prosecution presented Kirkup as a pornographer, and won. This was not justice. Nor is it justice that Kirkup's poem may now be found by anyone on the internet, and yet as far as I know he has never received any royalties for it.

I think some of us already saw the danger of the misuse of blasphemy law. We didn't foresee the Rushdie case, but we foresaw something like it. This case depressed me at the time, and I wondered if we could have played our case differently. Lemon didn't go to prison, but he shouldn't even have had to think about it. He was an innocent man. And Kirkup is a fine poet. I would testify to that all over again.