David Cameron will declare today that poverty is an "economic waste and a moral disgrace" as he pledges that a future Tory government would help the poorest in society.
In another symbolic break with the Tories' recent past, Mr Cameron will disown remarks by John Moore, one of Margaret Thatcher's ministers, that absolute poverty had been virtually abolished by the 1980s because the incomes of the poor had risen along with those in society as a whole.
The Tory leader will accept that what matters is relative poverty and the gap between the poorest people and the rest. Giving the annual Scarman lecture, Mr Cameron will say: "In the past, we used to think of poverty only in absolute terms... That's not enough.
"We need to think of poverty in relative terms - the fact that some people lack those things which others in society take for granted. So I want this message to go out loud and clear: the Conservative Party recognises, will measure and will act on relative poverty."
Mr Cameron will offer a different solution to the Government. He will argue that the answer is not to pay higher benefits but to tackle the root causes of poverty such as poor education and unemployment.