To be honest andrew it could be a number of things as a few of us are having similar problems but if you try these things first it might save you a trip to the garage.
Buy some BG244 and chuck it in your fuel tank.
Check all of your pipes going to and coming from your turbo and intercooler for splits/damage.
Clean your EGR valve and lubricate the valve stem inside.
Go for a decent trip on the motor way to regenerate your catalytic converter.
Thats what i would do first so if the problem persist or goes away then pop back and give us an update