Just one in ten London knife robberies was solved by police last year, data has shown, as leftist Mayor Sadiq Khan finally speaks up on the problem, begging the public to help police the city.

The new statistics, from London’s Metropolitan Police force, shows there was a fall in all cases of knife crime successfully investigated in the capital last year, as the number of recorded attacks shot up.

The so-called “sanction-detection rate” for knife robbery crimes, those that end in some form of sanction or conviction, has been falling since 2015, with Mr. Khan taking over in early 2016.

In 2015, 32 per cent of cases of violence against the person involving a knife was acted on, dropping to 27 per cent in 2016, and 23 per cent in 2017, a Freedom of Information request by Conservative London Assembly Members (AM) revealed.

However, for robberies involving a knife, police acted on just 11 per cent of cases last year. This plummeted from 20 per cent of cases in 2015, and 14 per cent in 2016.

Tory London Assembly Member Tony Arbour revealed the numbers at a meeting of the Assembly’s Police and Crime Committee Wednesday and questioned why police were following the “political line” pushed by the Mayor of blaming cuts instead of addressing the issue.

He asked if “the real reason why violent crime is increasing on London’s streets is the increasing belief that perpetrators will get away with it?”

Sophie Linden, Mr. Khan’s deputy mayor for policing and crime, replied by saying it “must make a difference” but said the police were perusing the same number of criminals as offences rose.

Assistant Commissioner Martin Hewitt, the head of Territorial Policing for the Met, conceded there had been a “very significant increase” in violent crime last year and there was “far too much knife violence”, but argued the crime wave was “stabilising”.

The revelation comes as Mayor Khan spoke out on Twitter about the knife crime crisis; once again blaming it on a lack of resources, an assertion that has been challenged in the past.

“Londoners have responsibility, too,” he said in a statement. “We’ve got to be the eyes and ears of the police – if you see something that you think is a criminal event, ring 999.

“We’ve got to help the police do their job in these difficult circumstances, keeping us safe.”