More than 100 leaders from the physical activity sector have written to Prime Minister Boris Johnson calling for urgent funding during the coronavirus crisis.
Football Association and British Cycling chief executives Mark Bullingham and Julie Harrington are among the signatories to the letter which calls on the PM to ring fence funding or risk creating health problems for a generation.
The sector has been badly affected by closures due to the pandemic and is now seeking the establishment of a Sports Recovery Fund to help protect jobs and leisure facilities.
"Grassroots sport, fitness, and wider recreational activity is proven to improve physical, mental, and social wellbeing. This makes our sector an essential service as our nation recovers from the damage caused by Covid-19," the letter, which has been seen by the PA news agency, states.
"Covid-19 has undermined our commercial revenue streams with both stadia and leisure facilities closed or greatly reduced in capacity. The impact of this will potentially lead to a lost generation of sport and activity.
"We are particularly concerned about the impact on those whose participation has been limited during the pandemic. Physical activity levels, especially in the most vulnerable groups, are significantly below where they were tracking pre-Covid-19. This is at a time when the government has committed to levelling up outcomes and opportunities across the country."
The letter continued: "We know your passion for the power of sport. You have set out your belief that sport drives positive change.
"This is, no doubt, hugely influenced by your role as Mayor of London in delivering the hugely successful London 2012 Olympic and Paralympic Games and the legacy vision for sport that event created.
"By placing sport and physical activity now at the heart of our nation's renewal and using it to drive new ambitions for health and wellbeing, we can create a strong, prosperous, resilient, and healthy nation for generations to come."
A study by grassroots funding body Sport England and Sheffield Hallam University published earlier this month said that every £1 spent on community sports participation and physical activity generates £4 for the economy in England, and that the sector contributes £85billion to the economy annually.