Since January, the capital has seen twice as many fatal stabbings as in the same period last year.
Across the UK, the number of reported knife crimes has been steadily rising since 2015, as have hospital admissions for people assaulted with a sharp object.
The Home Office’s six-week campaign, costing £1.35m, uses true stories of young people who have previously carried knives.
Using the hashtag #knifefree, the stories are being promoted via social media and a nationwide poster campaign.
As #knifefree was launched, Home Secretary Amber Rudd said: “The emotional stories at the heart of the new Knife Free campaign bring home in powerful fashion just what a far-reaching impact [carrying a knife] can have on a young person’s life.
“I hope any young person who is seriously thinking about carrying a knife listens to what the implications can be.”
In 2008, 16-year old Ben Kinsella was stabbed to death in north London in an unprovoked attack by a group of teenagers.
The Ben Kinsella Trust was set up in his memory to raise awareness about knife crime among young people.
Its chief executive, Patrick Green, told Sky News he welcomed the Government’s investment in the #knifefree campaign, but said it was just part of the solution.
“Since 2015, many youth services have suffered cuts,” Mr Green said.
“We’ve seen drops in police numbers across may forces across England and Wales.
“These are the tools that you need to address knife crime.
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“With less of those and an increasing knife crime problem I fear that, as bad as this week has been, I can’t see any immediate resolution to this.
“My worst fear is that this gets worse before it gets better.”