European leagues have until 25 May to tell Uefa whether they want to complete or cancel their seasons.
Football is suspended in all European countries apart from Belarus because of the coronavirus pandemic.
The Premier League has this week stepped up its plans to resume the season in what has been labelled 'Project Restart'.
Arsenal, Tottenham, Brighton and West Ham have opened their training grounds to players for individual work.
The Premier League league is hopeful of a potential 8 June restart and finishing at the end of July to fit in with Uefa's European competition plans. This would require full training to begin by 18 May.
Top-flight clubs will meet on Friday to discuss options for the restart.
Culture Secretary Oliver Dowden said he had been in contact with clubs about restarting the Premier League "as soon as possible".
Professional Footballers' Association deputy chief executive Bobby Barnes said: "We have been assured of the intentions of all that there would be no resumption unless guarantees of safety could be given to the players.
"The overriding principle for all parties is the health and safety of all participants on and off the field, and of course the wider public."
The Scottish Premiership is suspended indefinitely and the season could yet be declared over, a move already taken with the second, third and fourth tiers north of the border.
The Dutch top flight was abandoned on Friday with no promotion or relegation and no champions, while on Monday Belgian clubs postponed a vote on confirming the cancellation of their top flight until next week.
The deadline set by Uefa is referred to in a set of guidelines on 'eligibility principles' for European competitions that the governing body's president and general secretary have sent out to football bodies.
"Given the unforeseen and unprecedented situation [...] national associations and leagues are facing a situation whereby the completion of their domestic competitions may be at risk," they write.
Stakeholders are told they "should be in a position to communicate to Uefa by 25 May the planned restart of their domestic competitions, including the date of restart and the relevant competition format".
It adds: "In the event that a domestic competition is to be prematurely terminated for legitimate reasons […] Uefa would require the national association to explain by 25 May."
Uefa is understood to have set the date because of its next executive committee meeting two days later, when decisions on the restarting of the Champions League and Europa League may be reached. It is viewed as flexible guidance, rather than a rigid deadline.
Last week, after a video call meeting of all 55 national associations, Uefa made clear it wants on-field performance to determine which clubs make up next season's European club competitions, despite the current shutdown.
Uefa urged clubs to "explore all possible options" to finish their seasons.
It accepted that in "special cases" some could be cancelled, but asked authorities to use "a different format" if needed in order for teams to qualify for European competitions.
If league seasons cannot be finished, it said national associations would need to select clubs to qualify for Europe.
Uefa said it could "refuse or evaluate" selected teams if necessary.