Labout MP Yvette Cooper has accused the Government of failing to "grip" the scale of the knife crime crisis.
Ms Cooper, who chairs the Commons Home Affairs Committee, said she was "baffled" that the Home Office did not appear to have a "basic" assessment of the number of young people at risk.
The Labour MP for Normanton, Pontefract and Castleford flagged up her concerns during an evidence session with the minister for crime, safeguarding and vulnerability, Victoria Atkins, and a senior Government official.
Ms Cooper told them: "I'm baffled that when you have something as serious as this ... that you don't have a basic assessment of the number of young people who are at risk.
"The biggest challenge to you is not that individual things you are doing might not be worthwhile, it's that you just have no grip on the scale of the problem."
Ms Atkins told the committee that her department does use data, such as to pinpoint where resources for tackling knife crime should be allocated.
She said: "There are different measures and my officials spend a great deal of time looking at those measures to see what's happening on the ground and what's being done locally."
Ministers and police have come under sustained pressure over the response to serious violence.
Earlier this year, there were warnings of a "national emergency" following a spate of killings.
Figures published last month showed police in England and Wales recorded 40,829 offences involving knives or sharp objects in 2018, the highest number since comparable data started in 2010/11.
The number of homicides last year, 732, was the highest for any calendar year since 2007.
The Government says it is boosting police funding by more than £1bn, including council tax and money specifically earmarked for tackling serious violence.
Ms Atkins also noted that forces have financial reserves.
She told the committee: "Yes of course you've got to keep a buffer for emergencies, but if the taxpayer has given you money to spend on policing, please spend it."
The Government today announced that the final part of a £100m fund to combat serious violence has been allocated.
Home Secretary Sajid Javid said £12.4m will be distributed to 18 forces dealing with high levels of violent crime.
He said: "This money means forces can take urgent action, including more officers on duty in the worst affected areas.
"It takes a collective effort to tackle violent crime and I'll continue to work closely with police and partners to end this senseless bloodshed."
The announcement came as a new ministerial taskforce on serious youth violence, chaired by the Prime Minister, held its first meeting.
According to recent research, knife crime across Yorkshire and the Humber increased by 45 per cent between 2008 and 2018.
West Yorkshire and South Yorkshire are among seven police force areas where officers were recently granted new powers to increase stop-and-search activity as part of the fight against the problem.