Politicians must stop being "judgmental" about benefit claimants and accept responsibility for having created a system which traps people into dependency, Iain Duncan Smith has said.

Middle-class viewers were only "shocked" by programmes such as Benefits Street because the deep failures of the welfare state had previously been "ghettoised", he said.

And the Work and Pensions Secretary backed a fellow Tory minister's warning that voters were fed up with hearing "what we hate" rather than positive messages.

Mr Duncan Smith used a speech marking the 10th anniversary of the social welfare think-tank he founded to launch a defence of his major benefits shake-up.

It was something he would have wanted to do even if the Chancellor was not seeking deep public spending cuts as it would end a culture of dependence on handouts, he said.

The cabinet minister made direct reference to Benefits Street, the Channel 4 programme which focuses on the daily lives of several residents living in a Birmingham street.

It has caused controversy amid claims from critics that it has demonised residents and has turned poverty into entertainment.

Mr Duncan Smith welcomed the greater public exposure of a "tragic state of affairs" that at its worst meant people were "pushed into crime".

"With income inequality under Labour the worst for a generation, whilst the middle-class majority were aware of the problems in poor communities, they remained largely unaware of the true nature of life on some of our estates," he said.

"For too long we let these problems be ghettoised as though they were a different country.

"Even now, for the most part they remain out of sight - meaning people are shocked when they are confronted with a TV programme such as Benefits Street.

"The reality is that our welfare system has become distorted, no longer the safety net it was intended to be."

Speaking of those who resorted to crime, he said: " Such behaviour can never be condoned, but it is a tragic state of affairs - and a mark of how far the current system has failed - that people should feel pushed into crime by having their aspirations to make a living penalised."

Mr Duncan Smith - whose own tour of deprived council estates after being ousted as Tory leader in 2003 prompted him to set up the CSJ and embark on his bid to reform the system - said he "absolutely" backed comments made by Treasury minister Nicky Morgan.

In a warning about "language and tone", she told a Tory think-tank that Conservatives too often say that "we're anti this, we're anti-that, we don't like them, we don't want them here, we don't want them doing this".

"If we talk about what we hate all the time, we're not talking about what we like and what we want to do to help people who want to do well in setting up businesses or making our schools the best," she said.

"We never say actually we are on the side of these people, we want this to happen and we think this is great," she cautioned.

Asked if he agreed, Mr Duncan Smith told BBC Radio 4's The World at One: "Yes, absolutely. This is about life change.

"Our mission here should be about renewal, about getting people who have been locked away in the benefits system away from productive life back involved and engaged."

He went on: "The last thing that politicians and others should do is to be judgmental.

"In a sense we have created this system that entraps people. Our job is to reform it so that it gives reward to those who do the right things and actually gives people in places like that a real opportunity to get on up and play a productive part in society."

"I'm in favour of talking about what we believe will improve life, not always finger-wagging."

He said he preferred to think of "cuts" to benefit spending as " legitimate reductions" because people would be less reliant on benefits.

In the speech, he placed his radical shake-up of the system in the same Tory tradition as the anti-slavery movement of Wilberforce or the labour reforms of the Earl of Shaftesbury.

Pilots of the new Universal Credit system were demonstrating "remarkable" behavioural effects in terms of claimants' commitment to finding work, he said.

He also hailed "promising signs that the trend of bringing in migrant workers at the expense of British workers is being reversed" with 90% of the rise in employment over the past year accounted for by UK nationals.

With Chancellor George Osborne seeking another £12 billion of welfare savings in the two years after the 2015 general election, Mr Duncam Smith said they would be targeted at parts of the system "which are actually limiting people's horizons".

TUC general secretary Frances O'Grady said: "Iain Duncan Smith's welfare reforms have led to elderly and disabled people being kicked out of their homes for failing to pay the hated bedroom tax, while dying cancer sufferers have faced benefit sanctions for not finding work.

"To compare this Government-directed cruelty to the abolition of slavery is, frankly, offensive."