a4 avant iffy accelerator pedal

[pano amo]

Got some sort of problem with my a4 avant (2006). Theres a bit of movement in the accelerator pedal between me pressing it initally and the the pedal actually making the car move! Its very apparent at the lights or a junction when I'm stationary. I push the pedal forward and theres a sort of lull, then off the car goes. Is the throttle on the later a4 fly-by-wire or is it a mechanical or cable linkage? It wasn't there or certainly wasn't as bad when I bought the car from new two years ago. Even my wife who wouldn't be quick on the pedal has noticed this gap between pressing the pedal and then pedal doing its job.