Parents and pupils who assault teachers will face tougher sentences under Government plans to clamp down on violent crimes.
The Violent Crime Reduction Bill, due to be published this week, proposes to lengthen jail sentences and increase fines for those who attack teachers and other public service workers. If it is passed, the Sentencing Guidelines Council will decide the details next year.
The tougher sanctions have been welcomed by the NASUWT, Britain's second-biggest teaching union, which estimates from its surveys that a teacher is attacked every seven minutes.
Chris Keates, general secretary, said: "Stiffer penalties not only send out a powerful warning to would-be assailants but give a strong message to teachers and headteachers that they have the Government's backing in maintaining order and discipline."
The Bill will also give heads new powers to search pupils suspected of carrying weapons.
The National Association of Head Teachers and the NASUWT said that the searches, announced last year, could put its members in danger. But John Dunford, general secretary of the Secondary Heads Association, said schools would welcome the powers provided they were given guidance to help avoid allegations of assault.
"It is difficult to search pupils because staff fear they will be accused of assault. That can be extremely frustrating if you think a child is in possession of a knife."
Mr Dunford said that searches should always be carried out with at least two teachers present to reduce the risk of false accusations or violent resistance.
Other proposals include raising the legal age for buying knives from 16 to 18 and making it illegal for under-18s to purchase replica guns. Tougher sanctions will apply for firing air-guns at other people.
The Bill follows the death in 2003 of Luke Walmsley, 14, who was fatally stabbed in a Lincolnshire school corridor. Merseyside police revealed last month that children as young as seven were carrying knives into school to ward off bullies.
Deputy head Gary Dreher, 40, was left with severe cuts and bruises after he was attacked at the gates of St James's high school in Exeter by teenagers last September during an open evening. A 17-year-old was jailed for 10 months for the assault.
Mr Dreher said: "I don't think prison sentences are effective. Far better to spend the money on early intervention because by the time these young people are teenagers it is too late."