Confidence: It might be this.
Notes: One of 2 identical caterpillars found this Autumn. This one on hazel, the other on ash. It looks like the offerings in ukleps but there may be similar larvae? Barred Chestnut is common in the area, its foodplants seem quite varied though hazel isnt specified in Waring. Brambles, sallows and birches are mentioned -"and other woody plants".