I'm Dr. Jackie and I would like to try to help. I see you are offline, so I'll try to answer as quickly as possible. I did try to answer in Q & A so that I could have longer to respond; but for some reason, that function is not working at the moment.
My best answer is that we should try to chat about this in real time because I think this question is much too complex to answer just by typing back and forth with hours of time delay in between.
However, in the time remaining...I know you care very much for this individual; otherwise, you would not ask how you can try to find a loophole in the system that will allow you to see and spend time with him. I confess to not being an expert in the Domestic Relations arena in the UK, but I am very familiar with D. R. in the United States. And regardless of either country, your partner would not have spend time in jail had he not violated a court order, presumably not paying child support or something related to that.
So the big question right now in the time I have remaining is, "Do you really want to be with someone who is trying to avoid his responsibilities regarding his own child?" I know you are not involved with his former relationship person and her child. But if he is obviously avoiding/trying to skip out on his responsibilities to his own flesh and blood (eg., his child), think logically--if things do not work out with you, and since he has no blood relationship/connection to your child, do you really think he will be supportive of you and the child, especially if you have a serious argument or problems?
Things may seem good now, but as the cliche goes, "When the going gets tough, the tough get going." Statistically, I can cite you study after study that shows this to be true.
You may not like my response. This is probably not what you WANT to hear. But as a counselor, I am bound to provide my honest reaction to your issues/questions.
This person has a history of bad behavior. And you are asking how you can break the law to be with this person. Are you sure this what you want?
I am happy to chat further. I am available today 4 p.m-9 p.m. EDT
There is no more time in chat, but I'm happy to switch to Q & A or chat further now or later.