A proposal from Boris Johnson to "compel" children on the fringes of crime to join scouts groups to learn discipline has been slammed for being ill-defined and unrealistic.

The London mayor, who pledged to tackle knife crime in his election manifesto, was asked recently to expand upon a statement in his youth action plan, Time for Action, which contains plans to divert young people from crime.

During the launch on November 5, in Bounces Road Community Hall, Edmonton, Mr Johnson would not give any details of how much the plans would cost.

Under a heading: "Building character and responsibility, Project Titan" the plan states: "We will work with all uniformed organisations, such as scouts and guides and police... to spread their work throughout the capital... But more than that, we want their help with some of the most difficult kids, those on the fringe of criminality. Working with the police, probation service, the parole board and london councils, we want to use our powers to compel attendance at these organisations by those who need it. Scout troops and Army Cadet Squads are the kind of gangs we like. It's time to expand their turf."

At Mayor's Question Time last Wednesday, London Assembly member for Enfield and Haringey, Joanne McCartney, said: "You talk about using the police to compel those on the fringes of criminality. I am just wondering who enabled you to believe that the scouts would be happy with forcing children to go on their excursions?

"Our worry is that some of the language in the documents shows you have more questions than answers. A spokesman for the scouts has said that forcing (kids) is not what they are about."

Mr Johnson said the document was to provide "leadership" and "creative answers". He said: "90 per cent of this work is being done by london councils - what we are trying to do is create a whole youth strategy. I don't believe in forcing children into the scouts. But many people from youth offending groups said how they look forward to working with these groups.

"This document is not a blueprint, it is an indication of the things that we should be doing."

Time for Action is also billed as a "call to partners" such as the police and other agencies who have the power to enact proposals such as the idea of a seperate prison for first time offenders which is outside of Mr Johnson's jurisdiction as Mayor.

Ms McCartney will be one of a cross-party panel, the Youth Strategy Response Panel, set up to discuss Time for Action over the coming months.