La Liga clubs could come under a new UEFA Financial Fair Play system.
The likes of Atletico Madrid, Barcelona, Real Madrid, Sevilla and Villarreal are among the most likely to be impacted by the new rule.
UEFA have proposed new FFP rules to replace the current system, and the new rules will come into play if approved by the executive board.
The New York Times report that the new rules will mean clubs can only spend 70% of their income.
The income could be determined over a three-year period, which is broadly the system now.
According to the report, the new system, which would replace the current controversial system, would be introduced steadily over a three-year period.
During that three-year period, clubs would be able to spend 90% of their income ahead of that figure dropping to 70% after the adaption period.
It’s claimed UEFA wants to make the system stricter, so that clubs can only be within a margin of €10million.
Along with fines, it’s claimed clubs could be relegated from the Champions League to Europa League, Europa League to Conference League and so on if they are in breach.
UEFA are also said to be considering the possibility of deducting points from teams in the new Champions League format, which comes into place in 2024.
The group stage of the competition will instead take the form of a large league table, rather than the current format, which involves multiple groups of four.