Throttle unresponsive whilst driving

hi all,

   I have spent a while searching here and google but can't find any information on this issue. Owned the car for 9 months, 2007 1.9TDI . The issue is that occaisionally whilst driving the throttle is unresponsive, if you dip the clutch it will drop back to idle but won't stall, let the clutch up again and it drives as normal. I know there have been similar issues on mk4 golf etc where it has been the brake pedal switch but mine has the switch on the master cylinder so I have not been able to test this yet. When the issue occurs I have tried pulling up and waggling the clutch pedal around as I assume it will also have a clutch pedal switch? but this madeno difference.  This problem seems to be getting worse and occuring more often and also seems to happen more before the engine gets up to full operating temp. I have scanned with VCDS but there are no relevant faults showing. The car had a new battery a couple of months back.

Any ideas?

thanks