The most important thing to keep in mind is that Question Time is television. It is not the debating hall, a dinner party, down at the pub, or inside the mind.

Nick Griffin and many viewers, I’m sure, would have wanted, even expected, me to come across as an abrasive, point-scoring, shouty, finger-pointing black woman. That would have played into Griffin’s game plan, because that is the view of his party. The BNP portrayed me as a “black history fabricator” on its website. There was no way that I was going to live up to any negative mental pictures that it would have had about me, or of any other black woman. Even at the risk of looking “ineffective”.

It was clear to me within five minutes that the man was dangerously narcissistic. In America he would have been on David Letterman’s Late Show, an object of ridicule. He deserved to be taken apart forensically, based on the cartoon history on his website and which, most importantly, is its very foundation: some completely lunatic idea about “Ice Age Britons” and indigenous people. But in bringing that up, I broke TV Rule No 1 for a primetime programme: don’t go into long explanations.

On Question Time, you are only given an opportunity to speak when you’re asked to speak. It isn’t a free-for-all, a mêlée, even though it may appear to be. And you have to be pithy. I wasn’t.

But it wasn’t about me. It’s about the public, and this is as it should be. The public want to question and hear what their political leaders have to say. That’s why the programme is on BBC One.

Question Time is absolutely the right format for the general public to confront those who affect their lives. It is a show about politics and how politics is experienced by ordinary people. That’s the point of the whole thing.

The three representatives from the mainstream political parties rightly questioned Griffin on his politics, which are centred in race and ethnicity. His party exists for no other reason than that.

Not to have pinned him down to be more specific about his policies, not to have expressed their own revulsion concerning his past, not to have stated their own position in relation to that past, would have been absurd. He had never faced a national audience before. It was quite right for all of us to get clear about exactly what he means and what he stands for.

What was demonstrated was his inability to hold his own in the political arena. His answers were evasive, mantra-like platitudes and half-baked, baseless statements meant to resonate in the empty chambers of the minds of anyone who found him credible.

By exposing the two-bit rhetoric of his position, Question Time has shown that the emperor has no clothes. Now the long debate can begin. This long debate was never meant to be held on Question Time.

When I was asked on to the programme, I immediately thought of my father and my late mother-in-law, Joan. My late father, Ben, was stationed here during the Second World War as part of the D-Day offensive. He was born a sharecropper in Mississippi and had lived in a segregated society all his life.

In Britain he discovered a tolerance completely alien to him. He met white working-class people who treated him like a human being and Jamaican airmen who had flown in the Battle of Britain. They were black men who did not have to drink in segregated pubs. The American military had imported segregation to Britain during the war. There had been black and white pubs, even black and white towns.

The British landlords here rebelled, but those who did paid a price: they could be declared off-limits, suffering the loss of valuable revenue. But Britain, its spirit and its freedom, left an indelible mark on my father.

For the 50th anniversary celebrations he returned and had the opportunity to meet my late mother-in-law, Joan. Dad was the second black person she had ever met. I was the first.

But Griffin didn’t deserve to hear about their lives, or mine. He doesn’t care about the lives of non-white people. When he hears a tale of valour or service or dedication, he simply smiles and says “thank you”, as if he’s dispensing a tip.

But the Question Time audience had to speak, and it was they who said what had to be said. They were made up of people who had applied to come. They were a typical London audience, too, people representative of the range and diversity in that great city.

I’ve travelled up and down the country doing Question Time and have been in front of all kinds of audiences, but frankly, the ludicrous non-sequiturs and outright nonsense that Griffin was spouting would not have worked anywhere in this country. The British people simply have too much sense.

But if this is true, why does the BNP exist? Partly the reason for this lies at the feet of the three main political parties. They are largely responsible for the political vacuum that allows an absurd outfit such as the BNP to get anywhere.

I have lived here for more than two decades and have had the privilege of voting in two general elections since becoming a citizen. But this election leaves me with a feeling of complete ennui. This is not only because of the MPs’ expenses scandal, which is an outrage, but the general insular nature of the Westminster village. There is a lack of the “will to live” right along the entire political spectrum.

The problems in the economy have opened the door to racism. Out-of-work people, people who have lost their homes, their pensions, their sense of self-respect, blame The Other.

There is a vacuum, a yawning one, and the poison that is the British National Party is the result. But we can pull back from the brink. The BBC, by allowing Nick Griffin on to its airwaves, has exercised the highest definition of public service: it has informed us all and done so in a public arena. It’s called democracy.

Bonnie Greer is a playwright and deputy chairman of the British Museum

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