occasionally foot to the floor there's no power, lift off and press the pedal again and its back to normal. is this a dicky throttle position sensor? anyone had similar?

Could be - have you got Vag-Com? Could give the throttle a quick clean and reset it see if that helps.

If the throttles shagged they're not a cheap part to replace (over £200 new) :(

got a spare throttle body there to try off an s3 if its the same part? no access to vagcom but got a few friends who can

Yeah give it a whirl. Not sure if the throttle bodies are the same diameter though, the part number for the S3/LCR one is different. The intake pipework before the turbo is definately wider on the S3/LCR but not sure if after the turbo they're the same diameter or not (and whether the hole in the end of the manifold is the same size). You'll need Vag-Com to reset the S3 throttle body once you've fitted it anyway.

do you get any boost created?

yep

could be an issue with TC/abs sensors, Is sense's that your slipping so it opens the wastegate

Does it do it with ASR turned off?

yeah does it either way

dicky brake switch...

That was the issue?

dicky brake switch...

Was just about to say that

Sounds like mine did

that would make a lot of sense if that was the fault

yep!