Eight-five per cent of London’s heads know of families that are “living in hunger or fear of starvation”, a new campaign backed by the city’s mayor Boris Johnson claimed this morning.

‘London’s Biggest Breakfast’ aims to raise awareness and funds to support more breakfast clubs in the capital’s primary schools, ensuring that children from deprived areas start the day with a free, healthy breakfast and are ready to learn.

The startling statistic - quoted as the campaign, supported by the Mayor’s Fund for London, launched this morning - may be less than representative. The fund says it is based on a February survey of 160 London head teachers, of which only 36 responded.

But the result chimes with warnings from this Easter’s teacher union conferences about teachers having to bring in food to school for pupils.

It could also prove embarrassing for the Tory mayor, Mr Johnson, as the Conservative led coalition government faces claims that its policies are leading to people going hungry.

The survey also found that 97 per cent of the heads saw evidence of children starting their day without breakfast and more than nine in ten said they provided children with food in the morning because “they see evidence of hunger”.

Half said that said children were ill during the school day because they were hungry and “85 per cent believe that there is a food security issue with their pupils i.e. families are living in hunger or fear of starvation”, the poll found.

The campaign said the findings demonstrated “the urgent need for organised breakfast clubs to be available in schools”.

Mr Johnson said: “Getting involved with London’s Biggest Breakfast is an easy way for companies and individuals to help London kids get a healthy breakfast and set them up for their school day.”

On Saturday the NASUWT union released the results of a survey of nearly 4,000 teachers which found that more than a quarter had to bring food to school to help hungry pupils.