Tory Philip Davies (Shipley) said there had been a decline in the use of stop and search powers because police officers fear a backlash if they do so.
MPs also heard warnings of the "utterly horrific" treatment of girls in gangs after Tory former minister Sir Christopher Chope asked why so many perpetrators and victims of knife crime appeared to be male.
-> Hull students devastated by death of Libby Squire as new safety measures announcedSpeaking during an urgent question, Mr Davies added: "It can't be a coincidence that that has coincided with a huge surge in knife crimes and people who have been killed through knife crimes.
"Can the minister give me some assurance that we will go back to trusting the police officers to get on and do their job in the way that they know best without them fearing some kind of politically correct witch-hunt if they decide to stop and search someone that they think is worth stopping and searching.
"We must trust police officers to do the job, to keep us safe, because they know better than anybody in this House what needs to be done."
Home Office minister Victoria Atkins replied: "Stop and search is a vital tool in the police's armoury in keeping people safe on our streets. We absolutely want to give confidence to our officers that they have this power and that they can use it in accordance with the law.
-> These constituencies in Yorkshire have the most signatures on the revoke Article 50 petition"Interestingly, the rate of arrests arising out of stop and searches has increased in recent years with this intelligence-focused approach but it remains a vital tool and the police have our absolute confidence should they choose to use it within the law."
Sir Christopher (Christchurch) later said: "Will this knife crime summit be examining the issues to why so many of the perpetrators are male and the victims are male and relatively few are women?"
Ms Atkins said: "I would just urge a note of caution in that we know that, sadly, girls are involved in gangs as well.
"Indeed, the youth workers and former gang members I meet have very much emphasised to me that girls are beginning to be ensnared in these gangs as well and the ways in which some of these girls are treated by those gangs is utterly horrific and beyond most people's imagination, so we need to support those girls who are ensnared in gangs as well."