Some English Football League clubs are on the "brink" of collapse but cancelling the season will be a "last resort", says chairman Rick Parry.
With plans for some fans to return in October not proceeding the EFL aims to secure a rescue package to help cover an expected £250m loss in ticket sales.
The Premier League, government and other sources have been asked to help.
"We need specifics and clubs need answers and reassurances very soon," Parry told the BBC.
- Premier League awaits EFL £250m coronavirus 'bailout' proposals
- Delayed return of fans could have 'devastating impact'
A number of clubs and sporting bodies have already expressed their concerns after plans for fans to return to sporting events in England were postponed.
Speaking to BBC Radio 5 Live, Parry outlined the situation faced by many EFL clubs.
"In League One and League Two more than 30% of the revenues come from gate receipts," he said.
"We've consistently said we need up to £250m and that was based on the losses of last season and an assumption that we play the whole of this season without crowds.
"Some [clubs] are on the brink. Some would have been without Covid-19. We have kept nearly all of them intact so far and of course there is a prospect that if we can't get a package some will go to the wall.
"In a normal year our clubs rely on £440m of owner funding to keep them afloat. That is the size of the losses they make."
Both League One and League Two ended early last term after a vote by clubs in June - helping to limit losses.
But Parry, who remains "confident" that financial assistance will be forthcoming says cancelling the season at those levels could have disastrous consequences.
"We need League One and League Two to remain relevant. If we go into hibernation we might not come out of it," he added.
"They are the heartbeat of their communities and we need them playing football and coming out of this stronger."