I think I have discovered the clinching argument for closing the House of Lords. It is the presence in that chamber of a peer called Lady Tonge of Kew. Last week the baroness (formerly the Liberal Democrat MP Jenny Tonge) opened a debate about Botswana with an attack on the Gana and Gwi bushmen of the Kalahari. She suggested they were trying to "stay in the stone age", described their technology as "primitive" and accused them of "holding the government of Botswana to ransom" by resisting eviction from their ancestral lands. How did she know? In 2002 she had spent half a day as part of a parliamentary delegation visiting one of the resettlement camps into which the bushmen have been forced. Her guides were officials in the Botswanan government.

Lord Pearson of Rannoch, a man with whom I seldom find myself in sympathy, alleged that something was missing from her account: the trip, he claimed, including first-class air travel, was funded by Debswana. Debswana, a joint venture between De Beers and the government of Botswana, owns the rights to mine diamonds in the bushmen's land in the Kalahari.

"I took the precaution," Pearson reported, "of hiring my own interpreter, so I was able to hear exactly what some of the 200 bushmen and their families who had recently been forcibly resettled in a camp at New Xade were saying. I heard them describe it as a place of death, where they had nothing to do but drink, take drugs and catch Aids. Many of them felt that they had been evicted because Debswana wanted their land for its diamonds ... I, for one, came home more convinced than ever that a great injustice was being done."

He might have added that Debswana was being assisted by Hill and Knowlton, the public-relations company famous for the unsavoury nature of its clients. It advised the Chinese government in the wake of the Tiananmen massacre, set up lobby groups for the tobacco companies and coached the girl who told the false story about Kuwaiti babies being thrown out of incubators that helped to launch the first Gulf war. Until recently, Hill and Knowlton provided "administrative services" to the parliamentary group of which Tonge and Pearson are members. Now this task is discharged by the Botswanan high commission, whose line on the bushmen is identical to Lady Tonge's. Its work on this issue is coordinated by Dawn Parr, a former employee of Hill and Knowlton. The PR company boasts on its website about how it "generated support" for Debswana among "UK parliamentarians".

Tonge's timing was also unfortunate: she made this speech just six weeks after Survival International launched its campaign to try to discourage people from characterising indigenous people as primitive and living in the stone age. It has its work cut out. Three days after Tonge gave her speech, I heard the BBC's Indonesia correspondent telling the World Service that the West Papuans' "way of life, until recently, had more in common with the stone age than the modern world". He was probably not aware that John F Kennedy approved the annexation of West Papua by the Indonesian government with the words: "Those Papuans of yours are some seven hundred thousand and living in the stone age." Stone-aged and primitive are what you call people when you want their land.

The animal theme comes up quite often too. "How can you have a stone-age creature continue to exist in the age of computers?" asked the man who is now Botswana's president, Festus Mogae. "If the bushmen want to survive, they must change, otherwise, like the dodo, they will perish." The minister for local government, Margaret Nasha, was more specific. "You know the issue of Basarwa [the bushmen]?" she asked in 2002. "Sometimes I equate it to the elephants. We once had the same problem when we wanted to cull the elephants and people said no."

When speaking to an international audience, the government takes a different line. Like Lady Tonge, it insists that the bushmen must be evicted from the central Kalahari game reserve for their own good. "It has never been easy for government to extend social services to the sparsely populated remote rural settlements. People have thus been encouraged to move into settlements with schools, health clinics and other training and vocational opportunities."

"Encouraged" is an interesting word. Ten days ago a United Nations committee noted "persistent allegations that residents were forcibly removed, through, in particular, such measures as the termination of basic and essential services inside the reserve, the dismantling of existing infrastructures, the confiscation of livestock, harassment and ill-treatment of some residents by police and wildlife officers, as well as the prohibition of hunting and restrictions on freedom of movement inside the reserve". People who have tried to remain in their lands have been tortured, beaten and starved.

Since 2002 the Gana and Gwi have been seeking a court order allowing them to return to their lands. But the government, aware that eventually the bushmen's supporters will run out of money, has been dragging out the case for as long as possible. It has now repealed the section of the constitution to which they were appealing.

When, in the 1960s, the Innu of Canada were evicted from their lands by similar means and for similar purposes, they immediately fell prey to alcoholism, petrol-sniffing and suicide; 50% of the population now has diabetes; 35% of the Innu children in schools in Labrador have foetal alcohol syndrome. Suicide rates are around 12 times higher than the national average. This will be a familiar story to anyone who has witnessed the forcible relocation of indigenous people. Though the Botswanan government refuses to keep separate statistics for the evicted Gana and Gwi, they appear to be succumbing to the same psychic and physical collapse with extraordinary speed.

Lady Tonge later explained that she used the word primitive to mean belonging to "another age". But the Gana and the Gwi, like indigenous people everywhere, exist today, and what they do belongs to the present as much as anything anyone else does. There is no scala natura of human validity that places them at the bottom and us at the top. Faced with a different set of ecological conditions and economic constraints to ours, the bushmen trying to return to their lands see that their traditional practices and technologies - or some of them at any rate - are more likely to ensure their survival than sitting in a tin shed drinking moonshine. They can also understand the benefits of western healthcare and education, but they want to use them if and as they choose, not as the paternalists in Botswana or the House of Lords determine.

I would like to be able to say that Lady Tonge's characterisation of the bushmen is itself primitive, meaning it belongs to another age. But this would not be true. Not only are indigenous people still widely characterised as savages in order that their land can be seized; but there is still a House of Lords in which unelected people such as Lady Tonge talk like Victorian missionaries of the need to rescue people from their darkness. The incumbents of the House of Lords are just as much part of the modern world as the iPod and the bushman's hunting bow. Unlike the bushmen, however, they do seem to merit eviction.

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