Hi. 2008 HSE Auto with 36000 miles on clock.

Just noticed a new minor issue. When the engine is running an in Park there is a loud click from the gear selector lever when the brake pedal is depressed. No noise at all when driving or when changing from R to D, only when pressing the brake in P. You can feel it clunking the gear lever too - I think it must be the mechanism which prevents the gear lever being moved without the brake being pressed, but I have never noticed such a loud click before.

Anyone else had this?

Yes, you thought right.
The intensity of sound varies a little from car to car.
If it was silent and then became louder, maybe something became loose.
You can easily reach the mechanism and see if it is something wrong.
There is a thread in Technical section about removing the gear lever.