Fabia locking offside front wheel

 I currently have a problem with my 56 plate 1.4TDI whereby under braking, the offside front wheel is locking, generally when the road surface is rough. This can be under normal - not heavy - braking. Its hard to tell if the ABS is cutting in on that wheel. There are no warning lights, or error messages when doing a scan. It was recently MOT'd, where the front axle braking force results showed 213 kgf left vs 243 kgf right with 11% imbalance - both wheel showing a lock.