In the wake of Drummer Lee Rigby’s murder in Woolwich Muslim children at risk of radicalisation by their parents should be taken into care, Boris Johnson has said.
The Mayor of London called for children at risk from extremism to be removed from their families to stop them being turned into "potential killers or suicide bombers".
Mr Johnson said "fatal squeamishness" had developed over intervening in the behaviour of certain groups in society but insisted there was a need to be "stronger and clearer in asserting our understanding of British values".
Some children are being "taught crazy stuff" in the vein of the vile beliefs of soldier Lee Rigby’s killers Michael Adebolajo and Michael Adebowale, he added.
In his weekly column for the Daily Telegraph he said: " We know that the problem of radicalisation is not getting conspicuously worse - but nor is it going away.
“There are a few thousand people in London - the "low thousands", they say - who are of interest to the security services; and a huge amount of work goes into monitoring those people, and into making sure that their ranks are not swelled by new victims of radicalisation.
"What has been less widely understood is that some young people are now being radicalised at home, by their parents or by their step-parents.
“It is estimated that there could be hundreds of children - especially those who come within the orbit of the banned extremist group Al-Muhajiroun - who are being taught crazy stuff: the kind of mad yearning for murder and death that we heard from Lee Rigby's killers.
"At present, there is a reluctance by the social services to intervene, even when they and the police have clear evidence of what is going on, because it is not clear that the 'safeguarding law' would support such action.
"A child may be taken into care if he or she is being exposed to pornography, or is being abused - but not if the child is being habituated to this utterly bleak and nihilistic view of the world that could lead them to become murderers.
"I have been told of at least one case where the younger siblings of a convicted terrorist are well on the road to radicalisation - and it is simply not clear that the law would support intervention.
"This is absurd. The law should obviously treat radicalisation as a form of child abuse.
“It is the strong view of many of those involved in counter-terrorism that there should be a clearer legal position, so that those children who are being turned into potential killers or suicide bombers can be removed into care - for their own safety and for the safety of the public.
“It must have been dreadful for the family of Drummer Lee Rigby to listen to the ravings of his killers as they were finally hauled away to the cells and, one hopes, to a lifetime of incarceration.”
Asked whether the Prime Minister would back Mr Johnson's proposal for children at risk of radicalisation to be taken into care, David Cameron's official spokesman said that the issue was being kept "under review".
The spokesman told a regular Westminster news briefing: "The Prime Minister very much agrees that through strategies such as the 'prevent' strategy, we want all agencies to be working together - local authorities and central government and other agencies.
"We always keep this area, like all areas, under review. Individual decisions are for the courts, but we will keep these things under review."