The New Zealander, who has coached in Ireland and Wales, wants the top eight teams in the Celtic League to qualify for Europe, regardless of what nation they come from.
Under the current system, Wales are always guaranteed three qualification spots for the Heineken Cup, while the Irish have the same.
Gatland has welcomed the new semi-finals play-offs, which will be introduced for next season's Magners League, but he believes Celtic rugby chiefs should go one step further.
"The Magners League semi-finals are great but I don't think Wales, Ireland or Scotland should have a divine right in the European Cup," said Gatland.
"Why not make it that the top eight teams in the Magners League qualify for Europe, regardless of what country they come from.
"That means everybody is under pressure and you have to perform. It can only make everybody stronger in the long-term."