car is idling low?

I have recently had the clutch replaced on my Audi A3, 1.8 T Sport (1998).Since then the engine idles low when you start the car up, pulsating and occasionally cutting out. The accelerator pedal moves slightly on its own.
I would like to know if having the new clutch fitted could have caused this as the problem never occured before,- if anything the idling was high .Any suggestions greatly appreciated.