Being excluded from school has been described as the "tipping point" that leads to children picking up knives as it was revealed more than 22,000 people were caught with knives or dangerous weapons across England and Wales in the last year.
Youngsters who are taken out of lessons are at risk of becoming involved in violence and being exploited by gangs, according to a report by the All-party Parliamentary Group on knife crime.
It is calling for an overhaul to break the links between school exclusions and knife crime.
More than 17,500 boys aged 14 in England and Wales carry a knife or weapon, the cross-party group said, and a third of those arming themselves have had weapons used against them.
Official figures show that children in England's schools were permanently excluded on 7,900 occasions in 2017/18 - a 70% increase since 2012/13.
There was also a 54 per cent rise in fixed-term exclusions compared to 2012/13.
The group, made up of more than 50 MPs and peers, says that mainstream schools need to be more accountable for the children they exclude and action is needed to ensure that excluded pupils get a decent education.
"Too many children are being socially excluded and marked as failures, with tragic consequences," the report says.
Read more: The Sharp Edge: A Yorkshire Post investigation into the devastating impact of knife crime in Yorkshire
"All too often the moment of school exclusion is the tipping point that leads to young people picking up knives.
"It's increasingly clear children outside of mainstream schools are at serious risk of grooming and exploitation by criminal gangs. Professionals talk of the 'PRU (pupil referral unit) to prison pipeline'. We must act now to stop the flow."
Kayleigh Pepper, whose brother Richard Pepper was stabbed to death outside his home in Hull in June 2015, has campaigned tirelessly to educate young people on the dangers of knife crime.
Miss Pepper, 32, is working alongside Humberside Police and Hull pastor Mo Timbo as part of the #NoMoreKnives campaign which visits secondary schools across the Humberside Police force area, educating thousands of children.
"Every city across the country is doing something to keep their own streets safe and police forces are supporting initiatives like ours and we have got to keep getting our voices heard and raising the roof for our campaign.
Read more: Yorkshire's victims of knife crime
"It saddens me every time we hear of another stabbing because I automatically resonate with that family because I know exactly what they are going through - that pure emotion and heartache. It really is such a difficult time."
Miss Pepper also admits that campaigners and the public can only do so much to raise awareness of the dangers of knives.
She said: "The police need to carry that power and significance so people start looking at them with respect.
"The police need to work with the public to engage and challenge the perception that carrying a knife is not normal."
The group sets out a series of recommendations, including a call for a government review of the use of part-time education for excluded pupils.
Sarah Jones, APPG chair and Labour MP for Croydon Central, said: "The number of children being excluded from school and locked out of opportunities is a travesty. Often these children have literally nowhere to go. They are easy pickings for criminal gangs looking to exploit vulnerable children.
"Excluding children must be a last resort. But we hear all too often of schools stretched too thin to provide the wrap-around support struggling children need. Cash-strapped councils can't manage the increasing number of excluded children in need of alternative education."