|A. When you have a previous employer who is delivering negative messages about you, there are a couple of messages you can deliver in return.|
In the first place, you should reopen a dialogue with this employer and express your concern over his tendency to turn your employment verification into employment vilification. You should reemphasize your various successes on the job, your positive dealings with him, and the importance of his staying within the spirit of the former company's policy on providing references.
At the same time, you can lessen the impact of this previous employer's messages by letting a prospective employer know what this reference is probably going to say. Tell the prospective employer about what happened on this job, successes and failures, and be sure to emphasize how much you have learned, grown, and developed since then.
This will help set a positive context for a prospective employer to interpret anything your previous employer may say or imply, and it will simultaneously reduce the element of surprise. If you combine this approach with positive references from other previous employers, it's checkmate for that negative reference check.