The Home Secretary attempted a thin argument against, relying, it seemed, almost entirely on one sentence of the Wolfenden Report published 27 years ago. And when Teresa Gorman bemoaned the fact that the debate had been all one- sided, the Deputy Speaker promptly called Ian Paisley, who proceeded to make an ass of himself and a mess of his argument.
The debate was won, but the vote was lost. It is of course, utterly disappointing that the Commons did not accept the basic principle of equality before the law. An age of consent at 18 might be marginally - very marginally - less discriminatory than 21; but it remains discriminatory. It enshrines injustice in law. And it may be worse than that: the Home Secretary is now reported to be saying that he will issue guidelines to the police that will ensure stricter prosecution policies for those aged 16 and 17 than exist at present. He didn't tell us that on Monday evening.
I will be relieved if Monday night's decision means even one fewer prosecution of a gay man aged 18. But I will be deeply alarmed if it leads to several more prosecutions of gay men aged 16 and 17.
It simply cannot be right that a young man at 16 or 17 can choose perfectly freely and legally to have a relationship with a woman, but cannot decide to have a relationship with a man. 'A young man needs time,' said Michael Howard in attempting to justify how it might be that a two-year difference was necessary. But the logic of his argument, of course, is an age of consent for all men, of whatever sexuality, at 18, and for all young women at 16.
Anything of this kind would be preposterous nonsense; and his entire argument flies in the face of all the expert evidence from the British Medical Association, the Royal College of Psychiatrists, the National Association of Probation Officers and countless other bodies.
We have ended up with a fudged compromise - in typical House of Commons fashion - that is in reality totally indefensible. Nothing in Monday's debate indicated why the age of 18 was the right one to go for. If you breach the basic principle of equality, what logic can you advance for setting an arbitrary and different age?
The argument for equality will not go away. As long as inequality remains embedded in the statute book, there will be a constant demand for its removal. The need now is for all those who have campaigned so effectively on the issue to vow to carry on that campaign. There is understandable anger and frustration among many people, gay and straight alike, who argued so strongly for change. I hope that everyone can now channel their energies into a committed continuation of the campaign. 'We will be back' must be the clear message to Parliament.
The first opportunity may well be presented to us by the European Court of Human Rights. A case has been brought by three young gay men, arguing that a discriminatory age of consent breaches the Convention on Human Rights, of which Britain is a founder signatory. The court will make its decision on this case later this year, and the chances must be good that it will decide that the discrimination is unacceptable. If that happens, then Parliament - and the Government - cannot but take notice, and Parliament will have to consider the matter all over again.
Perhaps in those circumstances some of our reluctant colleagues who this week demonstrated that they were afraid of the idea of equality will wish with hindsight that they had been braver on Monday night. But then, I suspect you can divide the opponents of 16 into two categories. One consists of those who were genuinely hesitant about a reduction in the age of consent all the way to equality at 16. I believe their hesitancy was misplaced, and that on calmer reflection they will come to recognise that. Just as, two or three years ago, I would never have dreamt that we would have achieved even the result that we did on Monday night, opinion will continue to move in a progressive direction. The more the sensible, rational case is made, the more people will be won over. If we have learnt anything from the democratic history of our country, it is that you have to keep trying to make any progress - but eventually you do, even if it is one step at a time. Inequality at 18 is not the last word on this issue.
The other category of opponent, however, is less amenable. These are the people who are deeply prejudiced, and who moreover want to impose their prejudices on others. These are the MPs who were muttering as the result was announced on Monday night: 'That'll teach them.' These are the MPs who intervened at varying stages in the debate, in varying stages of inebriation, to lower the tone with varying degrees of homophobia. These people will never be won over to the idea of equality. It is perhaps useless to try persuading them; we must argue boldly against them.
The argument, after all, is a basic and simple one. In Monday night's debate, I quoted from a poem by A E Housman:
Oh who is that young sinner with the handcuffs on his wrists?
And what has he been after that they groan and shake their fists?
And wherefore is he wearing such a conscience-stricken air?
Oh they're taking him to prison for the colour of his hair.
In this country we do not discriminate against people because of the colour of their hair. We do not discriminate because someone happens to be left-handed. We do not - or should not - discriminate on grounds of race. But we do discriminate, and the law discriminates, against people who have a different sexuality. And so long as that is the case, the campaign to change the law must continue.
It ought to be a fundamental principle of democracy that the human spirit should be allowed by society to develop and flourish in its full diversity. Protecting and endorsing that diversity is what this issue is all about. It is a matter of deep sadness to me that, by a small majority, my parliamentary colleagues did not accept this point. But time is a great changer of minds. And I haven't the slightest doubt that we will be returning to this issue again before very long; and that the lapse of time, the making of the arguments, and the continuing plight of young gay men of 16 and 17 will have caused minds to change. Fundamental human rights cannot be forever denied.
Chris Smith is Labour MP for Islington South and Finsbury and shadow environmental secretary.