Tony Blair has denied that the breakdown of society was responsible for Britain's gun and gang culture, arguing that the problems ran "far, far deeper" than broken homes.
The Prime Minister told his monthly Downing Street press conference that tackling those difficulties was not about "marriage versus lone parents".
"The debate is about how you target measures specifically on those families, some of whom will be lone parents but some of whom will be couples," he said.
"That's the issue. The issue is whether you've got this generalised social breakdown - which I dispute - or whether in actual fact what you have is a specific problem with specific families that have been left behind by the general system."
Mr Blair said that "of course" marriage was "a good thing".
But he continued: "If our concern is those groups of kids or their families who are shut out of society's mainstream who are causing problems for themselves and their families, my point is .... recognise that the problems of these families go far far deeper.
"Unless we are prepared to take, I think, quite tough measures with support at a very early stage then we are not going to deal with this problem."
He described the events of recent weeks - including a spate of shootings of teenagers in south London - as "horrific".
Mr Blair said the hard core of problem families were a "special case" who had to be dealt with differently.
"If you end up saying there is a general problem then you can talk about tax breaks for marriage, extra money on tax credits, extra child benefit.
"All of those would help all families.
"My point is, if your actual worry are those families down at the bottom who are completely shut out from society's mainstream, we are kidding ourselves if we think those policies are going to help."
He went on: "Those families are families who, fortunately are a small number, but their problems are so intense and so profound and they are so shut out from the normal way of living in our society that unless you are prepared to intervene at a very early stage ... you are not going to deal with it."
