The poor now have a new champion in Iain Duncan Smith. And David Cameron clearly believes that his hapless predecessor’s analysis of our ‘broken society’ can steal the cause of social justice from the left.

It is, to be sure, hard not to witness this transformation without a wry smile at the very least. But, for all that, there is in fact a shift in Conservative thought; one that we will regret not taking seriously sooner rather than later. At first sight the central argument –that only a robust defence of the traditional family can save us – sounds very familiar. The language of ‘responsibility’ and ‘self-help’ strengthens the impression that this is a nostalgia trip, combining the social philosophy of Thatcherism with the politics of John Major’s ‘back to basics’ fiasco.

Nevertheless, the right’s argument has in fact shifted in one significant respect. For one of the salient features of Breakthrough Britain is that it repeatedly claims to acknowledge that poverty can be the cause of the social breakdown it describes; that it is part of a vicious circle in which the effects of poverty deepen that poverty. When Peter Lilley was attacking single mothers, the only victims were the taxpayers – virtuous citizens subsidising the ‘choices’ of welfare scroungers. The new Tory social justice analysis is that the poor are victims too. If welfare dependency and social breakdown make us all victims of the welfare state, then the Conservatives want to make the case for the minimal state a matter of social justice. That would be a neat tactical trick, but it also emphasises what has not changed. You need not scratch far beneath the surface to find the traditional Conservative assumptions about the ‘deserving poor’ – the causes of poverty are still individual choices, not structural disadvantage. Conservatives naturally slip back into the language of moral rather than social breakdown.

For, in the Tory lexicon, ‘family’ has always been a proxy for ‘private’ and an ideological bulwark for individualism (Thatcher understood this well). This takes us straight back to private ‘choices’ as the source of long-term poverty, rather than an analysis of the way in which these choices are conditioned and constrained by social structures. For the ‘undeserving poor’, now read the ‘undeserving family’. And how can the family alone, any more than the individual, pull itself up by its bootstraps?

This is the gaping hole in the claim that the family can break the cause-effect cycle of poverty. Nor can the Conservative family, precisely because of this association with individualism, be an intrinsic part of the other half of the proposed Breakthrough – a vigorous voluntary sector that educates the individual in the values of community and mutual obligation.

Nevertheless, the response to the report highlights how ‘family’ is going to be a key ideological and political dividing line between left and right. So the left must do more than expose the inconsistencies in the Tory account. A centre-left conception of family remains a work in progress. Instead of seeking to circumvent the language of morality, obligation and social virtue, we should be there to embrace this debate directly, on our own terms.

One approach here would be to concentrate on is the place of the family in a genuinely public space, in which we come to learn the value of mutual obligation. But this must come through meaningful participation, not through the mere receipt of services contracted out to a ‘third sector’. Instead we need a vision of the way in which disadvantaged families can engage as active participants in welfare decisions; not as the meek and grateful recipients of a conservative vision of charity, but as citizens exercising a say in the processes that distribute the aid to which they are entitled.

This takes the family away from the private and into the public sphere. In making this journey we should allow the emergence of a far greater emphasis on political voice to displace the consumerist language of ‘choice’ that we have inherited too uncritically from the right. Choice is important in a progressive politics, but this does not mean that we should allow it to crowd out other values. We should also seize the language of ‘civil society’ and give it a meaningful content that distinguishes it from the right: real participation – not the Conservatives’ ‘participation’ through work – and a sense that families are not a bulwark against the state, but potentially part of its crucial decisions.

That, of course, would require us to honour a basic assumption that is the true precondition of breaking the poverty cycle, and which is anathema to the right: equality of social status. It is now time for us to once again embrace this argument.