BRUSSELS (AP) — The Eurovision song contest continued to spawn unprecedented controversy, days after the winner was crowned, with the 27-nation European Union lambasting organizers on Monday for their “incoherence” in banning its flag from the concert hall during the final.

In an unusually sharp letter, EU Commission Vice President Margaritis Schinas wrote to the Swiss-based European Broadcast Union, which organizes the contest, that its ban contributes to “discrediting a symbol that brings together all Europeans.”

In a contest already full of controversy, the European Commission said it plans “a very lively discussion” with the organizers over the ban. Even though the 27-nation EU did not compete as such, many of its member states did, and the star-spangled blue flag is often seen as a unifier for all involved.

Schinas wrote that “such actions have cast a shadow over what is meant to be a joyous occasion for peoples across Europe and the world to come together in celebration.”