The ECA is the body which represents all professional clubs in Uefa, and the only one Uefa recognises.
It has said 💰 it is "strongly opposed" to the new league, and held an emergency meeting on Sunday after news of its creation 💰 broke.
Representatives from the Super League clubs did not attend.
This includes Juventus chairman Andrea Agnelli, who was chairman of the ECA 💰 but has resigned from his position.
What is the ECA?