Good cop, bad cop
They want open access to UK markets and Junker is creating problems.
The only people in Europe who wholeheartedly believe in an "ever closer union" managed Politburo style from Brussels reside mostly in, well, Brussels. As it has become more arrogant and its decisions and powers more arbitrary the EU has become a very unpopular institution across the continent. Fear of the consequences of a disunited Europe, and greed of the suckling "piigs", has kept this disenchantment on a slow simmer.
But Merkel helped bring it to a boil with her own heavy handedness, and her rank stupidity in allowing a million militant Muslims through the gate. She must now be seeing the writing on the wall and is scrambling to repair her own image and political future. Setting up Junker as the evil fall guy and isolating him in this drama is a start, but it won't do much to help her with Germans pissed off about the immigration catastrophe. There's a heavy political bill still coming due on that one.