Well, if I didn't just stumble across evidence of this in the words of a company itself. Being the sad man that I am, I was recently trawling through company responses to the BIS discussion paper on exec pay that led to the incoming pay reforms. I was specifically looking for views on the idea of employees on rem comms. And in one company's response I came across this as one of the reasons why this would be A Bad Idea -
Difficulty in preventing other employment issues affecting the discussions.So the Code says that rem comms should be sensitive to "pay and conditions", but a company is worried that employee representation would lead to "other employment issues affecting [rem comm] discussions".
When I get a bit more time I'll see if I can find some more like this.