Relationship problem - help needed!

Hi, 2 years ago, I had an emotional affair, which lasted about 3 weeks. I told my partner about it, and took the consequences, which have lasted until now. We separated for a while, and decided to get back together and work through it with a relationship counsellor. (We did this during the separation also) The causes were not simple, and were the result of events and a lack of communication on both sides. I won't go into them now. I have the opportunity to work in the same organization (big government organization, and the person I was involved with no longer works there, and is about 2000km away, and about to get married. My partner has said previously, she will not have me working there again, unfortunately, my current job will not last, and this new one will. My question is, how would I broach this subject without causing pain, and further issues. I don't want to hurt her, and have had no contact with the other person since it happened. It is looking like I will have to choose between my relationship or a job. Is that that the case? I don't want to be unemployed and reliant on my spouse given the current tenuous circumstances. I know what I did was wrong, but how do I work through this without losing something. Thank you for any understanding comments and replies.

Hi, the problem is that it will be a reminder, she asked me not to work in that government department again, and it will be hard to explain. I feel stuck, and could really do with some advice. Thank you