Baroness Warsi’s glamorous middle sister, something of an Asian fashion guru up in West Yorkshire, has selected an outfit for her to wear when she takes on the BNP on Question Time next week. It is a jewel-bright salwar kameez and the dupatta — the scarf that cascades over the shoulder — is in the pattern of the Union Jack.

The Shadow Minister for Community Cohesion is unconvinced, but to me the symbolism is irresistible: an Anglo-Asian Boudicca! When Sayeeda Warsi says “I want to ask Nick Griffin what about me isn’t British”, her Dewsbury accent is broader than the Pennines. Both her grandfathers served with the British Army in Indian sappers regiments, her great-uncle was interned by the Japanese in Burma, her father came to Britain with just a few quid and now owns a factory; she and her sisters know the words to Anglican hymns and Muslim prayers.

Say what you like about her politics, as a person Lady Warsi embodies hope and possibility: that the complexities of being British, Muslim and a woman can be happily accommodated within a cheerful, self-confident whole. And she is brave too — has a pop at her local imams over polygamy as doggedly as she will take on the BNP.

As Lady Warsi and I discussed her battle plan at a drinks reception, David Cameron happened to wander over. It seems that he does not share Sayeeda’s fighting spirit, was not happy at all, he said, that the BNP was to be given a platform. “It reminds me of when I was at Oxford during the 1980s and Gerry Adams came to speak at the Union. It makes me uneasy. I don’t think the BBC should have done it.”

I couldn’t tell whether he was being disingenuous, using the BNP as another chance to take a swipe at the Beeb. But in any case, when he was at college, Sinn Féin was proscribed and, since politicians have chosen not to proscribe the BNP, the BBC has little choice but to represent a party that, even in a paltry European election turnout, received one million votes and won two MEPs.

This week an editorial in The Guardian, agreeing with Mr Cameron, opined that the BNP “rightfully belongs under a stone”. But the Left’s long-held stance of no platform for racism or fascism, no longer holds when it is not merely the ooze and slime of bootboys or SS-crockery-collecting ideologues beneath that rock. The stone is being pushed up by a mass of angry and alienated souls who, amid the churn of the global economy, livelihoods undermined and undercut by cheap and diligent Eastern European labour, grasp at nationalism’s twin straws of nostalgia and vengeful rage.

They are not all bad people, this one million. They are not fascists or, I’d wager, when it comes to everyday human encounters, even reliably racist. Like the BNP-voting pub landlord whom I met in Sipson, the once-thriving village turned into a transient settlement by the threat of the Heathrow extension, they feel bitter, powerless and unheard. Yet when Lady Warsi from Dewsbury — a town with the biggest BNP vote in Britain — said that she believes such folk have legitimate concerns, Labour, bizarrely, tried to brand her a BNP sympathiser.

The Government’s persistent refusal to have an open discussion about immigration and its consequences — to dismiss anyone who tried to raise or even measure it as racist — has created a strange disjuncture between what people were told and what they saw in their own streets.

The Tories “Are you thinking what I’m thinking” strategy at the last election kept debate at the level of euphemism and innuendo. Jointly the big parties handed the BNP a total monopoly on a powerful and emotive issue.

Moreover, the growth of Islamic extremism has proved a boon to the BNP, providing it with a bogey man who is not only “alien” but has — in the 7/7 bombings — taken up arms against his own country. “Western values, freedom of speech, democracy and rights for women are incompatible with Islam, which is a cancer eating away at our freedoms,” Mr Griffin said recently. And as 30 frothing fools from Islam for UK yesterday waved banners saying “Sharia for the Netherlands, Freedom Can Go To Hell!” at Geert Wilders, the visiting Dutch far-right politician, it looked as if these mirror-image extremists truly deserve each other.

But this also illustrates the dearth of discussion about the proper relationship between civil liberties and religious belief. The British Left, until recently, has been hamstrung by its tired Seventies multiculturalism: branding attacks on hardline clerics or those pushing Islamified school uniform for girls as bigotry, refusing even to condemn practices such as forced marriage or female genital mutilation. The Left has spread a balm of tolerance over the most intolerant of all.

The BNP thrives on a lack of mainstream debate. Its favoured growing condition is darkness, it gains strength from appearing a repository of unspeakable truth. It peddles its myths and smears quietly on the blogosphere when it needs to be exposed.

There is much trepidation that the Question Time format is too fast and soundbitey to take the BNP fully to task, that even a line-up of four against one will be inadequate to contain a slippery, artful Mr Griffin. Or that he can be dealt with only if a Panorama special is commissioned to expose him. Or if he was strapped into the Mastermind chair, under an arc lamp, interrogated by the joint forces of Jeremy Paxman, Anne Robinson and all available Dimblebys.

But Mr Griffin is just a man. Garlic and silver bullets are not required. Just logic, debate and maybe even ridicule. Certainly it was better this week that Mr Wilders was permitted to bring his Thunderbird puppet hairdo to Britain for a day trip than enjoy the glamour and martyrdom of a barred door.

It is only a shame that on Thursday alongside Lady Warsi there will not be more British black or brown faces. Bonnie Greer, the Chicago-born playwright, has a powerful Obamaesque life story to tell, but it is not, in this context, the most persuasive. Where is David Lammy, Kwame Kwei-Armah, Kelly Holmes, Meera Syal, Sanjeev Bhaskar, Ian Wright? The heft and thrust of reason is one weapon: but better still is the face of someone fully at ease in their black-British skin. I hope that Sayeeda, warrior queen, wears that Union Jack scarf.

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