The roots of the confrontation date back two years when Germany's cost-conscious leading agencies got together under the umbrella of the German Art Directors' Club to determine which awards they would and would not enter. They were acting perfectly properly. The explosion in the number of creative awards is causing the coinage to be debased and agencies fail in their duty to staff and clients alike if they don't keep costs under control by restricting entries to only the most prestigious contests.
What has stung the Cannes organisers is the agencies' decision not to enter Eurobest, which they also run. Now, in a silly display of "tit-for-tat", the Germans are to be cast from the Cannes inner circle.
Perhaps most startling of all is the twisted logic with which the festival seeks to justify its ban. Its argument that the issue is about "freedom" looks a bit limp when set against the loss of 200 German Eurobest entries.
"It is intolerable that, in a democracy, people cannot make their own choices of what to do or what not to do," it says. Indeed it is, and the Cannes chiefs might do well to remember that well-known saying about pots and kettles.
The Germans have pledged to continue talking to the organisers to get the ban overturned while mobilising support among the international creative community. It's not that they intend to boycott Cannes, they say, but they rightly warn that a long-running dispute would be bound to diminish the interest of German agencies in it.
The festival may believe its place at the top of the global awards pile justifies its high-handed approach. For now it may be right but it has no room for complacency. While it's true that agencies always moan about the cost of the annual bunfight only to return for another fleecing the following year, there are some ominous straws in the wind. Major clients are showing increasing interest in awards which link creativity with effectiveness.
Many have long regarded Cannes as an indulgence - and agencies fail to take note of those views at their peril.
For the time being, the best hope is for a swift outbreak of common sense.
In adopting such a childish attitude the Cannes organisers diminish themselves and their event.