Children as young as 12 could be caught up in the criminal justice system for breaching civil orders if the government introduces promised measures to tackle knife violence, a London criminal defence firm has warned.

The Home Office announced last month that it will amend the Offensive Weapons Bill to introduce knife crime prevention orders. London firm Hodge Jones & Allen is worried the orders are a 'knee jerk reaction' to reduce the record number of fatal stabbings in England and Wales.

In a letter to the Home Office, the firm's youth team, led by associate Caroline Liggins, says the government has not consulted with youth offending teams, social workers, knife crime experts or solicitors who will have to deal with the orders on a day-to-day basis.

For an order to be made, a court would have to be satisfied that the defendant possessed a bladed article without good reason, in a public place or school, on at least two occasions within a two-year period. The court will able to impose restrictions such as a social media ban.

Breaching the order, which can be imposed on children as young as 12, would be a criminal offence. The firm says: 'This means that a teenager, who is merely suspected of carrying a knife, could be banned from social media, then imprisoned for using social media, without ever having being convicted of a crime.'

The team says children may have been coerced by an adult into carrying a knife or armed themselves because they are afraid they will be stabbed by their peers. 'The KCPOs will probably be ineffective for many who are subject to them because there is no support built into the proposals to help children and young people move away from those forces which cause them to carry weapons,' the letter says.

Earlier this month Home Office ministers were asked how such orders will tackle knife violence.

Asking an urgent question in the House of Commons, Labour MP Vernon Coaker said: 'Instead of introducing the orders, the home secretary should be chairing Cobra. This is a national emergency. This is a national crisis. Up and down the country people will wonder why the government are not using the full force of the state to tackle it. They need to help the young people who are having problems with knife crime and tackle the criminal gangs who ruthlessly exploit them.'