How do you know it is a left wing union?
You probably read it in the Mail ,
The snpl is the most important union in air france, but with the politict they made, snpl is loosing some of is influence with the direction.
In air france the only way you have to make thinks change is to put big pressure, if not all managent explain you: too expensive, not relevant and so on.
by the way, sorry for my english, not my mother tongue!