Is It Okay If I Call You an Ass, or Would That Be Wrong?

Over at Florida Blues, we see that our eloquent Commander in Chief wonders if it is okay to call the President of the EU a 'piece of work' to his face:

In terms of your Prime Minister, he's a -- interesting guy. He's a lot of fun to be around. He promotes, uhh, serious business in a, in a, in a way that, uhh, endears himself to people. And so, uhh, I think his presidency has been an important presidency for the EU during difficult times, and he's handled it well. And, umm, I was gonna say he's a piece of work, but that might not translate too well. Is that all right, if I call you a piece of work?

As Gatorchick points out, calling someone a 'piece of work' is a bit undiplomatic in any language.