Kimberley Kitching is smart, charming and engaging. She has been a Melbourne councillor, a lawyer, a political adviser and a senior union manager. Kitching ticks many Labor boxes.

But Bill Shorten made a terrible call backing her to replace Stephen Conroy in the Senate, a plum role once held by Labor giants John Button and Gareth Evans.

Mr Shorten's decision to back Ms Kitching (pictured) to replace Stephen Conroy has shocked Labor MPs on the Left and Right.

It's not how she got the job; most Labor politicians, even the good ones, get their start through an ugly factional knife-fight. It is not even her significant role in the amoral political culture that dominates and is hollowing out Victoria's Labor right faction.

There are two main issues, one uncomfortable for the Labor sisterhood and the other undeniable: her contribution to the ongoing factional abuse of the disgraced Health Services Union.