Just though I'd give an update on this; I popped the plastic cap off the egr actuator (I say popped but it took a fair effort with a pry bar to get it off!) then cleaned the cam lobe and bearing with some brake cleaner and worked it back and forward - it was initially sticky. I then used some red rubber grease on the lobe and popped it back together, after a drive the fault code has now cleared.
Nice easy and free fix!
This is the offending lobe which needs greased:
