Sticky footbrake

[Germs]

I have an '06 SL 500 and if it is left for a few days with the footbrake applied it increasingly sticks on - it feels like the pedal isn't lifting when the brake is released but I don't know if that is a mechanical linkage back to the brake meaning the fault could be anywhere in the line (?)Any ideas, prefer to do it myself if feasible as a sop to my masculinity (wife laughing behind me as I type!).