It must have been the first time that the Ice Age had been dragged into the heat of contemporary political debate.

Madeleine is missing the point which Nick Griffin, if I understood him correctly, was making, which was a perfectly reasonable one, no matter how loudly and unreasonably "British statists" (which most nationalists  have now become) and others may seek to demonize it as "racist".
Obviously, no one lived in what are now the British Isles when it was covered by hundred's of metres of ice. Thus the relevance of the Ice Age when discussing Britain's, or rather, northern Europe's, indigenous population.

Since the end of the last ice age, Europe's peoples (tribes) have been mixing, amongst themselves and, to a lesser extent, with people from neighbouring regions, i.e. North Africa, the Middle East and western Asia. In contrast, there was very little mixing, until very recently, with people's from beyond these neighbouring regions, i.e. with non-Caucasians.

I cannot imaging there are many people with a valid claim to being entirely "indigenous" to these islands, certainly not myself. However, most of us do have a valid claim to being "indigenous" to Europe, i.e. ethnic European (or "white people", if you prefer that term). This doesn't mean to say that we don't have any African or Asian blood in us at all (obviously we do, if one goes back far enough), but not enough to notice and thus be of much relevance in respect to our sense of identity and belonging (an interesting word, that: to "be-long").

And IDENTITY is what it's all about, because Homo sapiens (a very misleading name, that) evolved as much a "tribal animal" as a social animal. We need a tribe (or substitutes for it) to identify with. Being human, means being tribal as well as social, yet some, encouraged by the state, never tire of ridiculing or demonizing our tribal nature.

This is because the STATE has effectively (although quite inadequately) taken the place of our tribe, thereby laying claim to the subjugation, loyalty and commitment we are genetically programmed and socially conditioned to show towards it. Not that it forbids us from identifying with other substitute tribes (our circle of friends and family, employer, profession, football team, or whatever), provided our first loyalty is to itself (Britain, America, or whatever your state is).

It is the STATE (under the guise of being our primary tribe) which suppresses and manipulates our tribal nature for its own ends.
And what are these ends? As a human-evolutionary, i.e. Darwinian, view of civilization reveals (see my BLOG), they are to facilitate society's self-exploitation, to the advantage of its dominant individuals and elites (now predominant in business, politics and the media).