I've recently been offered a research contract in a UK University within a Mathematics and Statistics department. I've been trying to get into Mathematical research for a long time, but in the mean time to continue research, publish, and so on, and to pay the bills I've had to take research based academic jobs in a varied number of departments in a number of Universities from Engineering to Sociology ! My background is Computer Science, in which I have a PhD.
My question is: Is it likely that a UK University would permit staff to study a part-time PhD in a new field within the department, e.g. Mathematics. If so, would fees be wavered? Or would this not be allowed since I already have a PhD in Computer Science. I've had a rocky road to Maths, for one reason or another, and had to take jobs I sometimes felt divergent to where I really wanted to go, so it would be nice to "tidy up" the loose ends.