Sadiq Khan is “not up to the job” of running London as mayor, and has “undoubtedly” let knife crime worsen, says plumbing entrepreneur Charlie Mullins OBE, who now wants to run for the job himself.

Writing in Real Business magazine, the Pimlico Plumbers millionaire and anti-Brexit campaigner said he had “come to the opinion that my city of London, and its people, are being disgracefully neglected by the government, and it’s got to stop”.

He continued: “We are now experiencing a backlash against our great capital and its inhabitants, and somebody has to stand up for London and make its voices heard. This is why I have decided to stand as an independent candidate for London mayor, in 2020.”

Mullins, who writes about his political fascination of choice — stopping the Brexit process — frequently on his personal Pimlico Plumbers blog, was moved to point out that this interest was not his primary motivation in deciding to stand as an independent, remarking:

“My decision is not all about Brexit, but it is about the most powerful economic force in the country, generating billions of pounds in revenue, and paying for services all over the country, having its point of view ignored.”

He said Mr. Khan is not “the right man for the job”, describing him as “a mild-mannered solicitor by trade” and praising “big character” former mayors like Boris Johnson and Ken Livingstone.

When asked if Mr. Khan had failed on knife crime on Talk Radio Wednesday morning, Mr. Mullins said “undoubtedly”.

At the beginning of this month, new data revealed surging levels of violent crime in London last year under Mr. Khan’s watch – homicides were up 27.1 per cent, with youth homicides up 70 per cent, and serious youth violence up 19 per cent.

Robberies also rose by 33.4 per cent and burglaries by 18.7 per cent in 2016/7. In response, Mr. Khan promised to step up the use of police stop and search power, having previously promised to cut the practice.

As mayor, Mr. Mullins said he would fight to “retain London’s primacy, as an international trade centre, against huge opposition from cities like Paris and Frankfurt” and aim to put a London ambassador in Brussels.

He also said he would offer free travel for under-25s, and seeks to improve the wages of apprentices, remarking that he believed that young people have been hit hard by high rents and falling pay.

“The next mayoral election isn’t until 2020, and that might seem like an age away for some people, but already to me, as I think about all the things I want to achieve, it’s coming up very fast,” Mullins said.