More than £346m in "wasted" childcare funding should be used to get children more active and fight the growing epidemic of health issues among the young.

That's the message from ukactive, which has called on the government to redirect the Treasury underspend – allocated to tax-free childcare – to physical activity programmes.

In a report, called Generation Inactive 2 - Nothing About Us, Without Us, ukactive says the funding would help support parents to keep children physically active outside of school hours, with figures showing that over the summer holidays children lose up to 80 per cent of the fitness gained during term time.

The report also lays out a blueprint to tackle the barriers to physical activity for children and young people, mapping out the changes needed at every level in order to take a "more holistic approach to health, happiness and wellbeing" by focusing on active play and fun.

Generation Inactive 2 - Nothing About Us, Without Us is based on findings from what ukactive describes as the "largest consultation on children’s physical activity in recent times".

Other recommendations made in the report include developing schools into community hubs – integrating health, education and social care provision within schools – and for Ofsted to create an Inspection Framework that places pupil’s physical health and development at the heart of its evaluation schedule.

It also calls for all major political parties UK-wide committing to a 20-year public health campaign turn "generation inactive to generation active" by 2038 and for government to hold departments accountable for actively involving the views of children and young people in strategic health decision and policy-making.

“This is the least active generation ever, with evidence showing that inactive children become inactive adults at risk of a host of preventable diseases," said chair of ukactive Tanni Grey-Thompson.

“Unspent childcare funds from the Treasury can be put to better use and actually help parents where they need it most by providing fun and social physical activity programmes for children.

“There is no silver bullet so this report calls for a collective effort across government and every part of society to turn Generation Inactive into Generation Active.”

Children’s Commissioner Anne Longfield added: “We must make physical activity and play a public health priority for all children and young people, with practical solutions to make activities more accessible and appealing.

“Only by working together will we deliver the changes necessary to protect the health of future generations.”