'We must all pay to tackle broken Britain'

Soaring crime plus massive welfare bills for divorce, teenage pregnancies and workless households will bankrupt the economy unless checked, he said.

Speaking out in a return to the Conservative conference, Mr Duncan Smith claimed the cost of "breakdown Britain" was already running at £100 billion but that figure was set to double in the next five to 10 years unless there was radical action.

"This is a wake-up call to the country," he said. "If we carry on the way we are doing, then the cost of social breakdown will carry on spiralling upwards - and that will inevitably mean higher spending on the consequences and a higher burden of taxes.

"People will be spending more and more money just to mitigate what is going on in society, particularly in the inner cities." The former party leader gave a lecture style presentation with graphs to show how costs were rising. Spending on the criminal justice system including the courts and prison rose form £10 billion a year in 2001 to £23 billion last year, he said. The costs of youth justice services alone went up from £381 million to £648 million while police spending rose by a fifth. The bill for benefits paid to people of working age had gone up in a decade from £33 billion to £68 billion.