Banning junk food adverts on Transport for London (TfL) networks will not “dent” its revenue, insists the Mayor of London.

In May, Sadiq Khan announced he would be banning all junk food adverts on the capital’s transport network to tackle childhood obesity.

During Mayor’s Question Time yesterday Conservative London Assembly member, Gareth Bacon raised concerns that Mr Khan’s plans would cause a drop in TfL’s advertising revenue – of which junk food adverts contribute an additional £13 million.

But Mr Khan defended his decision.

He said: “I don’t expect the loss of junk food adverts will make a dent in revenue.

“Cancer Research research has shown that advertising does affect children’s food choices, the proposed ban will reduce a child’s direct exposure to this.

“If we don’t address it we are placing a strain on the NHS.”

A total of 40 per cent of children in London are overweight.

Mr Bacon said he had spoken to “industry experts” who were worried about the impact the loss of junk food adverts and wanted to know exactly how Mr Khan would be replacing the revenue from them.

Mr Khan said: “We will still have that advertising space.

“We don’t expect any change as we expect brands to advertise healthier food instead.

“Even if there is a small drop in advertising revenue that will be a small price to pay.”

But Mr Bacon, still unsatisfied with the answer, said Mr Khan was “wasting his time” and not answering the question.

He pointed out that the delay in the opening of the Elizabeth Line, which was due to open in December, was just another financial strain on TfL’s £1 billion deficit.

Mr Khan hit back, saying: “TfL has never had a surplus, it has always operated on a deficit.

“I am confident the team we have in place will make efficiencies.”