The high cost of school holiday activities is opening up a ‘major class divide' in the fitness levels of children, new research has revealed.

The report from ukactive shows that the most deprived primary school children see their fitness levels drop 18 times greater than the richest children over school summer holidays.

The research – which tracked the cardiorespiratory fitness levels of more than 400 children in 13 schools – found the most deprived children were able to run far shorter distances in September than they could in June. Meanwhile, the fitness levels of the most affluent children only dipped slightly.

The researchers said the prohibitive cost of many school holiday activities were putting the poorest children at risk of deadly diseases later life. They said the government’s Sugar Tax should be used to help fund out-of-term exercise sessions.

Dr Steven Mann, ukactive research director and lead author, said: ‘There's a growing class divide around fitness levels due to the summer holidays and the government must urgently address these Victorian-style health inequalities to give every child a fair chance of a healthy start in life.

‘Our research with Premier Sport suggests deprived children are being plonked in front of screens for hours on end, while their more affluent peers are able to maintain their fitness levels through summer camps and other activities.

‘Money from the £415m Sugar Levy should be used beyond the school gates to plug these gaps in provision and ensure all children can access physical activity and pick up vital healthy habits from an early age.