Junk food adverts are set to be banned on the London Underground as well as at bus stops in a new measure to tackle increasing child obesity.

Plans to introduce the ban across the Transport for London (TFL) network will be announced soon according to City Hall, once the London Mayor Sadiq Khan has fully studied the consultation responses. The Evening Standard are reporting that it could be as soon as next week.

It will prevent the promotion of foods high in fat, salt and sugar as the government try to reduce the number of overweight and obese children in London, which has become the worst city in Europe.

Of those children, 37.7 per cent are currently in their last year of primary school and the trend seems to be rising.

"When I started looking at the statistics for childhood obesity in our city, it was heartbreaking. What I was seeing was in the poorest parts of London childhood obesity was the worst," Khan previously said.

"In Barking and Dagenham, something like 45 per cent of Year Six children — these are 10 and 11-year-olds — are overweight or obese. You compare that to Richmond, where it’s 23 per cent. This is an issue of social justice — you have the poorest children overweight and obese.

"I was being told stories from parents and carers with children at a Tube station or a bus stop, they see these adverts for fast food outlets. The children put pressure on parents or carers to get the junk food.”

TFL generate around £147m a year from advertising and around £13m of that comes from food adverts that look set to be banned going forward.

It is a move that Amsterdam carried out earlier this year and there have been encouraging signs so far.

The Food Standards Agency will determine whether a food is high in fat, sugar or salt, but it is not yet determined whether the ban will encompasses junk food brands, or just the food itself, with Khan hinting that healthy alternatives could be advertised.