After graduation, he joined the Law Faculty at the University of Sheffield, where he was a lecturer from 1976 to 1990, a Senior Lecturer from 1990 to 1993, a Reader from 1993 to 1995, and became Professor of Public Law in 1995.
Ina dhiaidh sin, chuaigh sé i nDámh an Dlí ag Ollscoil Sheffield, áit a raibh sé ina léachtóir ó 1976 go dt� 1990, ina Léachtóir Sinsearach ó 1990 go dt� 1993, ina Léitheoir ó 1993 go dt� 1995, agus rinneadh Ollamh Dlí Phoiblí de i 1995.