Cancelling relegation from the Premier League this season would outrage Championship clubs, according to Rick Parry, the EFL chairman.
Parry added that the 2019-20 campaign needs to be finished by July 31 for sides outside the top flight.
Former Liverpool and Premier League chief executive Parry was giving evidence to the Digital, Culture, Media and Sport committee on the impact of the coronavirus pandemic.
Professional football in England has been suspended since March, with Parry revealing that clubs below the top flight are facing a £200million shortfall by the end of September as a result.
"Our end date realistically is 31 July because of the situation with contracts," said Parry of when the season needs to come to a close. "We can't go beyond July.
"Players and staff have been furloughed and to expect clubs to bring them back in now, to forgo the furlough, only to then find in a month they can't play would be a complete mess.
"We need within days to be taking decisions.
"We have a great deal of uncertainty around next season and the undetermined matter of when we'll be able to return with crowds, which for the EFL is absolutely critical.
"We're much more dependent upon the revenue and atmosphere generated by crowds than the Premier League."
Some Premier League clubs are reportedly uneasy about the competitive disadvantage of playing behind closed doors at neutral venues as they battle relegation, believing the drop into the Championship should be taken off the table.
However, Parry said: "The Premier League is aware of our position on that. There would be a degree of outrage from a number of clubs in the Championship and it would be a breach of the tripartite agreement."
Parry added that "lawyers are going to get wealthy" if relegation is scrapped.
Norwich City, Aston Villa and Bournemouth were in the relegation places when the season was halted. West Ham and Watford were only outside the bottom three on goal difference, with Brighton and Hove Albion two points clear of the drop.