Having thought a bit more about this problem, I initially agree that the noise did sound like rubber bushes 'working' although one would expect them to be quieter when wet.
However,my technician assures me that they have changed all the bushes in the entire LH suspension, but no difference.
So, one has to think what is different between the left & right sides of the car? The only minor difference seems to be weight, in that the battery is on the LH side and could perhaps generate some additional inertia during large vertical movements.
To my ears the sound is more akin to creaking floorboards, which leads me to think of body stress movements. Now, I have no doubt that all is safe at the moment, but if this stress, in time, culminates into fatigue cracks, perhaps around the suspension mounts, what then?
If Honda-UK read these posts, then will they please investigate with some urgency, as it it now obvious that the fault is not confined to just one or two cars.