Hi I had the same problem with my leon, on the Right hand bends only as well. I had decent tread all round on my tyres but better tread on the rear, swapping front to back so having better tread (only slightly better mind) on the front has cured the problem for me!!:D
 
Try vag com or any decent diagnostic scanner at a garage, launch, snap on etc socio, etc. Faulty abs sensor, or a broken abs ring on the hub.

Defiantly inspect the metal abs ring on the hub or shaft as some cars i have found have been broke and can be very hard to track down the problem as it isnt a fault just thinks it needs to use the abs/esp as it thinks there is something going on with that wheel