| The former England U21s and Saracens loosehead returns to Premiership rugby following a year out of the game and has been given six months to prove his worth to Saints’ coaching staff.
Harbut, aged 25, made his debut for Saracens against Northampton at Vicarage Road in 2000.
Head coach Budge Pountney said: “Luke wanted a chance to prove himself. He has got it and now it is up to him. There is no doubt he has the ability and we hope that he can rediscover his hunger for the game of rugby.” | 
