Panier de crabes
(n.) an intensely competitive situation or organization; the rat race, the daily grind [French]
Borrowed into English from French in the mid 1900s, panier de crabes literally means ‘basket of crabs’. Thanks to that literal meaning, some English speakers have conflated it with the English idiom a can of worms, and ultimately use it to refer to any intensely controversial or problematic topic. But in its original French, it is used idiomatically somewhat different.
Alluding to a fisherman’s creel full of crabs—one crawling atop the other in a vain attempt to reach the brim—in French, panier de crabes describes any mercilessly or intensely competitive situation, wherein all those involved ruthlessly attack one another or hold each other back in an attempt to come out on top.
Often it carries with it the implication that, as a result of their cutthroat behaviour, none of those involved will eventually succeed.
The phrase can also be applied more loosely to groups or organizations riven with squabbling or infighting—or, looser still, to the fiercely competitive dog-eat-dog world of professional work. However you choose to interpret it, it is nevertheless an expression worth remembering both at work, and perhaps on the morning commute.