Today i have noticed that when idling the revs are settling occasionally at about 1200 revs, a little blip on the accelerator returns it to 900 ish

I have also felt it when I am decelerating towards junctions

Any ideas / experience

is there a damper on the throttle that may be sticking ?

It has been known for accelerator pedals to stick a little. See if you can pull it up with your foot when it's doing it.

will do ta