Sadiq Khan on Monday quoted analysis of data from the Met Police, British Transport Police, the NHS and the Ambulance Service, before blaming rising knife crime on social exclusion, poverty and Conservative spending cuts.
Eustace Constance, Operation Director of Christian charity Ascension Trust told Premier he thought Mr Khan was just playing politics.
"I personally think it's election time and the mayor is doing what all politicians do," Mr Constance claimed.
"The information and the connection that the mayor has made are not new."
He added: "It isn't a revelation that ten to 16-year-olds are more susceptible to criminal activities after school hours. We were saying that over 16 years ago, that is why we started school pastors.
"Or that with 18 to 24-year-olds, violence happens over the weekend. We said that 16 years ago. That's why we started Street Pastors.
"We're not unique in that - the stats that he's quoting now have been available to the mayor, they've been available to the Metropolitan Police and others for many years."
There has been a spate of stabbings in the city this year.
The London mayor called for an end to the "nine year experiment to shrink the state" in a speech at a youth club close to where a person was stabbed less than 24-hours ago.
There have been at least 33 fatal stabbings in London this year, following a spike last year of 135.
Mr Constance said the Church could do more to tackle knife crime.
"I believe the Church is currently doing quite a bit," he said. But I also think that we can do so much more.
"So when we hear it was by design that the mayor gave his speech this morning in a youth club, you know, we have church buildings, let's open up our church buildings.
"Why don't we not bother about whether the local authorities are funding it, and let's fund it ourselves to make sure that there's a safe environment for people to come to."
Listen to Premier's Eno Adeogun speaking with Eustace Constance:
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.