It was no surprise to learn that Iain Duncan Smith was unhappy with the Chancellor's decision last week to increase out-of-work benefits by more than 5% when wages are falling. That decision, which runs counter to the entire thrust of the Welfare Secretary's programme for benefit reform, was apparently made at the behest of Liberal Democrats, despite the fact that one of the planks of the Coalition was the desire for a welfare system which would incentivise work.

A major national survey released yesterday shows the extent to which Duncan Smith is in tune with voters, and that the Chancellor would do well to listen to his views rather than those of Nick Clegg. The latest annual British Social Attitudes(BSA) survey reports that 55% of English people believe high benefit levels are deterring the unemployed from finding jobs, up from just 37% ten years ago. In both England and Scotland, support for increasing taxation in order to fund higher levels of welfare has declined steadily. Overall, British people nowadays are more likely to blame poverty on laziness or lack of willpower, rather than social injustice.

As benefit spending and welfare dependency increased substantially under Labour, popular support for such spending declined. Ten years ago, just over 40% of Britons surveyed said that benefits were too low and that this caused hardship. That figure has now fallen to 26%. People believe the transfers from working to non-working families have become too expensive. It also seems that the British have become more realistic about the ability of governments to “solve” the problem of poverty. The BSA survey reveals a widespread assumption that poverty will get worse: 56% believe that poverty will increase over the next ten years. That's the highest level of pessimism since the survey began.

In this context, it's particularly interesting that the BSA has this year, for the first time, included a specific set of questions on child poverty. The answers to those questions show that the British people have a deeper understanding of the causes and effects of child poverty than many politicians (especially on the Labour benches) give them credit for. Most people accept that there is such a thing as child poverty in Britain, about half think it has increased over the last ten years and the majority think it will go on increasing. Significantly, however, they do not see benefit payments as the answer. Only a tiny minority (4% ) think that the main reason for child poverty is that benefits are too low. 19% think the most important reason for child poverty is parental drug or alcohol addiction, 15% believe that the main reason is that parents don't want to work, and 10% believe family breakdown is the most important factor.

Iain Duncan Smith, as well as his former team at the Centre for Social Justice, will not be at all surprised by these findings. It was seeing the levels of addiction, family breakdown and benefit dependency in England and Scotland's most deprived housing estates that inspired IDS in the first place. But he should be heartened by the widespread consensus amongst the British people that the priorities he has identified are the right ones. When invited to give more than one reason for child poverty, 75% identified drug and alcohol abuse as a factor, 63% unwillingness to work and 56% family break-up.

That is why it is so disappointing that the Prime Minister and the Chancellor seem so ready to bow to Lib Dem pressure to adopt a failed, one-dimensional response to the problem of poverty in this country. Instead, the whole front bench should be confidently articulating the real reasons for deprivation and rebuffing Labour's calls for cash. Simply saying that the country can't afford to spend more because of the deficit implies that, in less straitened economic times, Conservatives would turn the spending tap back on.

As I argued here last week, the Labour government proved conclusively that spending more does not equal caring more. Nor does government spending solve deep-rooted social problems – indeed, it often exacerbates them. As IDS pointed out at the weekend, if parents are drug addicts then giving them more money will probably just enable them to spend more on drugs, not feed and clothe their children. The BSA report is a timely reminder that the public fully understands this.

The BSA findings are also an opportunity for the Prime Minister to break his silence on the question of support for the married family. Instead of allowing the Chancellor to whittle away support for two-parent families at low and middle income levels, David Cameron should be explaining how he proposes to fulfil his pledge to support marriage as a vital source of family stability and protection against financial hardship. On this issue, which at one time appeared to be so close to the Prime Minister's heart, the Welfare Secretary deserves full and vocal support from Downing Street.