Staff has long service but has a record of out bursts verbally towards other staff and managers, has being dealt with on all occasions under our disciplinary process but always seems to come to the end of his warning period before another occurence, recent incident were he has being given a task within his capability which he has done before and suddenly he has back pain and needs to go home, ask to complete the accident book he refuses starts to get abusive verbally and leaves.
I need to know how far I can go with him this time without just issuing a warning, waiting a period and it happening again.