All 42 SPFL clubs are being asked to consider a proposal that would lead to an increase in the number of teams within the leagues to 48 over the next three seasons.
The additional teams would come from B teams from Rangers and Celtic with two teams from each of Highland and Lowland leagues taking the number up to 48.
In the proposal there would be no relegation from the bottom of League 2 for the next three campaigns and by season 2024-25 there would be four leagues of 12 teams.
Clubs, who currently play in a 12-10-10-10 set-up, have been asked to indicate their approval or otherwise of the proposal by Wednesday 7 July -prior to the annual general meeting of the SPFL due to take place later in the month.
A previous proposal for Old Firm colts to play in a 16-team League 2 next season failed to attract enough support.
However, Celtic and Rangers colt teams have accepted a one-season invitation to play in the Lowland League in 2021-22.
Meanwhile, clubs in the SPFL have been informed they no longer have to supply negative Covid-19 PCR tests for players and staff ahead of matches.
The clubs now are required only to submit lateral flow tests for players and staff involved on match days.
However, should any positive tests come from LFTs then a PCR NHS test must be taken.
Over the past year clubs have had to pay out up to £4,000 per week for PCR tests, with the results submitted to the SPFL.