Half of all public leisure facilities in the UK could close by the end of the year without more government support, MPs have been told.
Huw Edwards, chief executive of trade body ukactive, said they needed a £800m bailout in the wake of the Covid-19 lockdown.
He said sports centres had “fallen between the cracks” of other services local councils have to provide in law.
Ministers say they are aiming to reopen facilities in England in mid-July.
Leisure centres and indoor sports courts have been closed since March and are yet to reopen in any part of the UK.
A date for their reopening has not been given anywhere in the UK apart from in Northern Ireland where it is provisionally fixed for 7 August.
Mr Edwards said there had been “frustration” that facilities had not been allowed to reopen alongside pubs and restaurants in England on 4 July.
He told the Digital, Culture, Media and Sport Committee he was hopeful the government would announce a reopening date “in the coming days”.
‘Sleepwalking into loss’
But he said his body, which represents leisure centres and facility operators, estimated around a third of facilities would not be able to reopen when allowed.
A £800m injection was required, he told MPs, to cover losses whilst they have been closed and make them sustainable in the “short to medium term”.
Mr Edwards said he felt there was a risk of “sleepwalking into loss of public leisure across the country,” and the sector’s non-statutory status meant it had “fallen between the cracks” when it came to funding.
Public leisure centres, swimming pools and sports halls are funded by local authorities, although often run by trusts or third-party providers.
However unlike other local services such as libraries, waste collection and road repair, councils are not legally obliged to provide them.
The Local Government Association says councils have “limited ability” to provide emergency support because of budget shortfalls they are facing themselves.
In written evidence to the committee, it said a “significant proportion” of charitable trusts that run leisure centres have “very tight” operating margins and small cash reserves to keep them afloat without fees income.
The government has given an extra £3.7bn in emergency Covid-19 funds to English councils to help them cope with pressures from the pandemic.
Mr Edwards told MPs leisure facilities would play a “key role” in improving public health in the wake of the virus.
He said this put them on the “frontline in supporting the NHS” and had led to “frustration” when they had been compared to other sectors that have reopened.
PM Boris Johnson has said a timetable for the reopening of indoor gyms and swimming pools in England will be set out this week.
Culture Secretary Oliver Dowden has previously said the government hoped to reopen gyms and leisure facilities in mid-July.
On Wednesday Health Secretary said ministers were working to get swimming pools reopened “as soon as safely possible”.
“The emphasis, of course, has to be on safely”, he said.
But he added: “The nature of swimming and changing rooms means that there are risks, and we have to ensure that those risks are properly taken into account.”