To understand the fury that a little-known MP, Greg Clark, has aroused on the Tory Right, you only have to turn his proposition around. Suppose that, instead of telling Conservatives that they should eschew Winston Churchill’s philosophy in favour of Polly Toynbee’s, he had enjoined Labour to embrace the views of Simon Heffer rather than the late John Smith. Can you imagine it?

Mr Clark, a thoughtful moderniser, actually makes a well-argued case in his paper for the party’s Social Justice Policy Commission. Although he deliberately cites Toynbee in order to stir up a little trouble (and hasn’t it worked a treat? A whole page in the Daily Mail headed “Winston v Polly” with quotes from each), he uses the left-wing columnist merely to support one proposition that has been Conservative orthodoxy, on and off, since the 19th century.

The question is whether we define poverty in absolute or relative terms. In other words, are people no longer poor because they own a TV and mobile, or should their circumstances be judged instead against those of the average Briton? Churchill believed that the welfare state should merely ensure that the poorest were housed and fed. Toynbee compares society to a caravan moving across a desert. If the stragglers at the back fall too far behind, they can no longer be counted as part of the same caravan.

The notion of relative poverty is hardly some radical socialist idea. Adam Smith, in The Wealth of Nations, was a great supporter: “By necessaries I understand not only the commodities which are indispensably necessary for the support of life, but whatever the custom of the country renders it indecent for creditable people, even of the lowest order, to be without. A linen shirt, for example, is, strictly speaking, not a necessary of life. The Greeks and Romans lived, I suppose, very comfortably though they had no linen. But in the present times, through the greater part of Europe, a creditable day labourer would be ashamed to appear in public without a linen shirt, the want of which would be supposed to denote that disgraceful degree of poverty which, it is presumed, nobody can fall into without extreme bad conduct.”

Linen shirts may no longer be the badge of social respectability. But as times change, so do our attitudes. Fifty years ago, people would not have considered a TV, a phone or an indoor loo a necessity. We do now. Then there were children who passed the 11-plus but could not go to grammar school because their parents couldn’t afford the uniform. Now we would be horrified if such an opportunity were lost. Of course poverty is relative.

What Mr Clark is arguing, therefore, is not new. But, as ever with David Cameron’s Tories, it is tone that matters. And the Conservative leader, in a speech today, will take the argument farther still.

Having agreed with Mr Clark that we should be concerned about poverty, however much richer society has become, Mr Cameron will say that government should think far more about the underlying causes of poverty rather than simply throwing money at the poor in the form of tax credits and higher benefits.

That is not to say that tax credits haven’t lifted many people out of poverty. But, because the Government has set itself targets to reduce the number below the poverty line — defined as 60 per cent of median income — it is much easier for ministers to concentrate on those at 59 per cent and to shift them up to 61 per cent than it is for them to tackle the seriously disadvantaged at the bottom. Gordon Brown has been acting like the headteacher who encourages his staff to concentrate on pupils heading for a D in GCSE, in the hope of bumping them up to a C and improving the school’s position in the league table of A*-C grades.

Government will never be able to abolish poverty simply by handing over more and more money. First, it will never have enough money and secondly, if benefits are too high, you trap people into dependence on them. It no longer pays to take work.

Instead, the Tory leader will say, we should try to address the root causes of poverty, such as family breakdown, poor educational attainment, lack of aspiration, drug and alcohol addiction, mental illness, lack of childcare and poor housing. He wants to tackle these not through government action, but by financing social enterprises and voluntary organisations, which are more human and less bureaucratic than the State.

There are some fantastic examples of social enterprises, led by energetic and inspirational figures, which succeed in transforming damaged people’s lives. But the reason we are all so impressed by Camila Batmanghelidjh of Kids Company is that she is such a one-off. The social enterprise sector cannot be scaled up enough to deal with all of society’s ills unless Mr Cameron brings in human cloning fast.

Labour has had a similar problem with education. Schools with energetic, inspirational heads can turn themselves around and become highly successful. But there just aren’t enough great headteachers to replicate this in all schools. Would that there were.

So what the Tories are doing is a good start. They have to persuade voters that they care about the poor and the socially excluded. They have to show that — like Polly Toynbee — they are prepared to become experts in the crunchy detail of social policy. And yes, something can be achieved by letting social enterprises do more. But it is not the whole solution. If there were a magic wand for waving away poverty, it would have been used long ago.

Times Recommends

• In the real world, the public sector must pay
• Playing politics in a land of double Dutch
• Be like the plinth people: not set in stone