The past few weeks have seen tonight’s BBC Question Time take up a lot of people’s time and energy because the leader of a political party is on the panel. Nothing at all controversial about that, perhaps a little unusual since you would not expect to see Gordon Brown or David Cameron there, but not a subject of controversy, surely.

Of course, the reason for the controversy is the politician is Nick Griffin, leader of the British National Party.

I’ve been following the various debates about whether he should be allowed with some interest, and cannot help but think of the quote attributed to Voltaire (but actually from a biography about him by Tallantyre): “I disagree with what you say, but will defend to the death your right to say it.”

A similar outcry was seen over an article in the Daily Mail by Jan Moir about the death of Stephen Gately. The article was, frankly, obscene – and I won’t link to it – and suggested Gately’s death was related to his sexuality, with some rather sordid implications. The result were complaints in their tens of thousands to the Press Complaints Commission – by far the biggest number for an article ever received and, apparently, totalling more than the PCC had received in total for the preceding five years.

Disregarding the rather sad and tawdry lives people like Griffin and Moir must lead to come to the conclusions they reach, the fact remains that in a free society they are at liberty to draw their own conclusions.

Personally, I find that hard to accept, but accept it I must. For the freedoms we all take for granted to apply to reasonable people like you or me, they must also apply to the unreasonable people like Griffin and Moir. But accepting that creates strength, it means we can start having the proper public debates that can kill off those poisonous views. And hitherto, without them, they have been allowed to flourish.

There are few things worse than knocking on the door when canvassing to discover a BNP supporter. There aren’t many, but they are around, and always have a hard luck story. Invariably they are unemployed, not because they are already drinking strong lager at 10am when I knock on their door (which is their right, after all) but because immigrants have taken their job. Often they need a new home, which they would have had, were it not for those pesky immigrants taking them all. If only, they opine, someone looked after them.

That’s what the BNP purport to do, and until now, because they were never given the platform, they were allowed to get away with it. Their charge that the mainstream parties were letting people down went unanswered. But now, finally, they have to articulate and defend their policies. And I’m confident they will be shown for what they are, rather vicious bullies who can only explain their own failure by pretending the system is rigged to favour others.

I think there is a valuable lesson here. The Griffins and the Moirs of this world are fundamentally intolerant people. Personally, I’d rather that intolerance be out in the open where it can be defeated, but for that to happen we also have to be tolerant of them. If we aren’t, every single time they are shut out of the democratic process it strengthens their anti-establishment credentials and helps convince people they might have something in what they say – and that’s how we get racist MEPs and GLA members.