The knife attack on a train in Cambridgeshire shows there is “clearly something going wrong with our society”, Kemi Badenoch has said.
Two men are being held in custody following the incident on Saturday where 11 people received hospital treatment, including two who remain in a life-threatening condition.
Police have said the incident is not thought to have been motivated by terrorism.
On Sunday, Conservative leader Mrs Badenoch said people should “wait until more facts emerge” rather than speculating about the causes of the incident.
But she also told the BBC’s Sunday With Laura Kuenssberg programme that politicians needed to have “a conversation” about the causes of violence on Britain’s streets.
She said people would be “asking the same questions that I’m thinking of right now” about why, despite measures to curb knife crime, “we’re seeing more and more violence on our streets”.
She added: “There’s clearly something going wrong in our society right now, which I believe all politicians of all parties need to have a conversation about.”
Comparing the attack to a triple stabbing in Uxbridge on Monday in which one man died and two others were wounded, Mrs Badenoch said: “We cannot be a country where people are innocently going about their business and facing this level of violent crime.
“It’s abhorrent, and it’s not something that we used to see before. What is causing it?”
Official figures released last month suggest knife crime has fallen in the past year, while NHS admissions for assaults with a sharp object are down 10% compared with 2024.
Overall violent crime showed “no statistically significant change” from 2024, but remains a third lower than it was a decade ago and 75% down on its peak in 1995, while homicides have reached their lowest point since at least 2003.
Senior Reform UK politician Zia Yusuf told the BBC: “We’ve got to ask ourselves why we are in this situation where, almost on a weekly basis, it feels like people are being traumatised by – in this country – by the fact that we have appalling knife crime.”
Presented with figures showing knife crime was falling, he told Sunday With Laura Kuenssberg: “While it might be good that it’s going down, assuming that the statistics can be relied upon, it’s still far too high.”
Mr Yusuf said he would not like to see increased security at train stations, saying it would impose “enormous friction” on the lives of law-abiding people “as a result of the actions of a tiny minority”.
But he argued for a significant increase in the use of stop-and-search powers “to saturation”, saying this would remove deadly weapons from circulation.
