If i remember correctly you can get rid of someone who has started work for you at the end of 12 wks but you must have had REGULAR appraisals about every 2 wks explaining where they need to improve, and what they are doing well. have written evidence that you have talked to him at each appraisal about is attendance and the need to improve or he will be let go. If there is no improvement at the end of 12 wks tell him he no longer works for you. I was a Department manager for Sainsbury's and we had these assessments for every new starter.